Replace {{anch}} macro with Markdown links (#13802)

* Replace {{anch}} macro with Markdown links

* Run updated script

* Run updated script (HTML-embedded MD, newlines in link)

* Catch embedded HTML better

* Fix slugs

* Revert commonly-used macros file

* Update files/en-us/web/api/mediasession/setactionhandler/index.md

Co-authored-by: wbamberg <will@bootbonnet.ca>

* Update files/en-us/learn/accessibility/wai-aria_basics/index.md

Co-authored-by: wbamberg <will@bootbonnet.ca>

Co-authored-by: wbamberg <will@bootbonnet.ca>

files/en-us/games/publishing_games/game_distribution/index.md

@@ -40,9 +40,9 @@ You don't have to tell people to search for your game in an app store with HTML5
 
 The vast majority of the traffic we are interested in — people playing HTML5 games — comes from mobile devices so that's something you will have to focus on if you truly want to succeed. Mobile devices are where HTML5 technology can truly shine and show its advantages. There's no Flash, and HTML5 is fully multiplatform.
 
-Trying to compete with desktop games directly is very difficult. You can put your HTML5 games into the same arena (see {{anch("Native desktop")}}, later on) and you should because it's good to diversify the platforms you support, but you have to remember that developers creating desktop games have years of experience, great tools and stable distribution channels. Many HTML5 games will target different market segments than native desktop games, e.g. simple time killer games to be played while on the move rather than huge immersive experiences. Such games are often designed to be played with two, or even one finger, so you can hold the device, play the game and be able to use the second hand for whatever you currently need.
+Trying to compete with desktop games directly is very difficult. You can put your HTML5 games into the same arena (see [Native desktop](#native_desktop), later on) and you should because it's good to diversify the platforms you support, but you have to remember that developers creating desktop games have years of experience, great tools and stable distribution channels. Many HTML5 games will target different market segments than native desktop games, e.g. simple time killer games to be played while on the move rather than huge immersive experiences. Such games are often designed to be played with two, or even one finger, so you can hold the device, play the game and be able to use the second hand for whatever you currently need.
 
-Saying this, desktop platforms can be used for distribution quite easily with the availability of wrappers that can help you prepare native builds of your game see {{anch("Packaging games")}}. It's also nice to provide desktop controls for your games even if you're mostly targeting mobile. Players are enjoying your games on any platform available, and desktop is one of them. Plus, it is usually easier to build and test the game first on desktop, and then move on to debugging mobile.
+Saying this, desktop platforms can be used for distribution quite easily with the availability of wrappers that can help you prepare native builds of your game see [Packaging games](#packaging_games). It's also nice to provide desktop controls for your games even if you're mostly targeting mobile. Players are enjoying your games on any platform available, and desktop is one of them. Plus, it is usually easier to build and test the game first on desktop, and then move on to debugging mobile.
 
 ## Publishing the game
 
@@ -70,7 +70,7 @@ There are also independent portals collecting interesting games like [HTML5Games
 
 ### Web and native stores
 
-You can also upload and publish your game directly to different types of stores, or marketplaces. To do that you'll have to prepare and package it to a build format specific for every app ecosystem you want to target it at. See {{anch("Marketplaces — distribution platforms")}} for more details of what marketplace types are available.
+You can also upload and publish your game directly to different types of stores, or marketplaces. To do that you'll have to prepare and package it to a build format specific for every app ecosystem you want to target it at. See [Marketplaces — distribution platforms](#marketplaces_—_distribution_platforms) for more details of what marketplace types are available.
 
 ## Marketplaces — Distribution platforms
 

files/en-us/games/techniques/tilemaps/index.md

@@ -89,7 +89,7 @@ function screenToWorld(x,y) {
 
 #### Rendering
 
-A trivial method for rendering would just be to iterate over all the tiles (like in static tilemaps) and draw them, subtracting the camera coordinates (like in the `worldToScreen()` example shown above) and letting the parts that fall outside the view window sit there, hidden. Drawing all the tiles that can not be seen is wasteful, however, and can take a toll on performance. **Only tiles that are at visible should be rendered** ideally — see the {{anch("Performance")}} section for more ideas on improving rendering performance.
+A trivial method for rendering would just be to iterate over all the tiles (like in static tilemaps) and draw them, subtracting the camera coordinates (like in the `worldToScreen()` example shown above) and letting the parts that fall outside the view window sit there, hidden. Drawing all the tiles that can not be seen is wasteful, however, and can take a toll on performance. **Only tiles that are at visible should be rendered** ideally — see the [Performance](#performance) section for more ideas on improving rendering performance.
 
 You can read more about implementing scrolling tilemaps and see some example implementations in [Square tilemaps implementation: Scrolling maps](/en-US/docs/Games/Techniques/Tilemaps/Square_tilemaps_implementation:_Scrolling_maps).
 

files/en-us/learn/accessibility/accessibility_troubleshooting/index.md

@@ -47,7 +47,7 @@ The finished assessment site should look like so:
 
 You will see some differences/issues with the display of the starting state of the assessment — this is mainly due to the differences in the markup, which in turn cause some styling issues as the CSS is not applied properly. Don't worry — you'll be fixing these problems in the upcoming sections!
 
-> **Note:** If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> **Note:** If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Project brief
 

files/en-us/learn/accessibility/css_and_javascript/test_your_skills_colon__css_and_javascript_accessibility/index.md

@@ -17,7 +17,7 @@ This aim of this skill test is to assess whether you've understood our [CSS and
 
 > **Note:** You can try out solutions in the interactive editors below, however it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## CSS accessibility 1
 

files/en-us/learn/accessibility/mobile/index.md

@@ -253,7 +253,7 @@ You should never set `user-scalable=no` if at all possible — many people rely
 
 Because the screen is so much narrower on mobile devices, it is very common to use media queries and other technologies to make the navigation menu shrink down to a tiny icon at the top of the display — which can be pressed to reveal the menu only if it's needed — when the site is viewed on mobile. This is commonly represented by a "three horizontal lines" icon, and the design pattern is consequently known as a "hamburger menu".
 
-When implementing such a menu, you need to make sure that the control to reveal it is accessible by appropriate control mechanisms (normally touch for mobile), as discussed in {{anch("Control mechanisms")}} above, and that the rest of the page is moved out of the way or hidden in some way while the menu is being accessed, to avoid confusion with navigating it.
+When implementing such a menu, you need to make sure that the control to reveal it is accessible by appropriate control mechanisms (normally touch for mobile), as discussed in [Control mechanisms](#control_mechanisms) above, and that the rest of the page is moved out of the way or hidden in some way while the menu is being accessed, to avoid confusion with navigating it.
 
 Click here for a [good hamburger menu example](https://fritz-weisshart.de/meg_men/).
 

files/en-us/learn/accessibility/test_your_skills_colon__html_accessibility/index.md

@@ -14,7 +14,7 @@ The aim of this skill test is to assess whether you've understood our [HTML: A g
 
 > **Note:** You can try out solutions in the interactive editors below, however it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## HTML accessibility 1
 

files/en-us/learn/accessibility/wai-aria_basics/index.md

@@ -194,7 +194,7 @@ Now if we use VoiceOver to look at this example, we get some improvements:
 
 Beyond this, the site is more likely to be accessible to users of older browsers such as IE8; it is worth including ARIA roles for that purpose. And if for some reason your site is built using just `<div>`s, you should definitely include the ARIA roles to provide these much needed semantics!
 
-The improved semantics of the search form have shown what is made possible when ARIA goes beyond the semantics available in HTML5. You'll see a lot more about these semantics and the power of ARIA properties/attributes below, especially in the {{anch("Accessibility of non-semantic controls")}} section. For now though, let's look at how ARIA can help with dynamic content updates.
+The improved semantics of the search form have shown what is made possible when ARIA goes beyond the semantics available in HTML5. You'll see a lot more about these semantics and the power of ARIA properties/attributes below, especially in the [Accessibility of non-semantic controls](#accessibility_of_non-semantic_controls) section. For now though, let's look at how ARIA can help with dynamic content updates.
 
 ### Dynamic content updates
 
@@ -307,7 +307,7 @@ We could go further with our ARIA usage, and provide some more validation help.
 
 > **Note:** You can see the finished example live at [form-validation-updated.html](https://mdn.github.io/learning-area/accessibility/aria/form-validation-updated.html).
 
-WAI-ARIA also enables some advanced form labelling techniques, beyond the classic {{htmlelement("label")}} element. We already talked about using the [`aria-label`](https://www.w3.org/TR/wai-aria-1.1/#aria-label) property to provide a label where we don't want the label to be visible to sighted users (see the {{anch("Signposts/Landmarks")}} section, above). There are some other labelling techniques that use other properties such as [`aria-labelledby`](https://www.w3.org/TR/wai-aria-1.1/#aria-labelledby) if you want to designate a non-`<label>` element as a label or label multiple form inputs with the same label, and [`aria-describedby`](https://www.w3.org/TR/wai-aria-1.1/#aria-describedby), if you want to associate other information with a form input and have it read out as well. See [WebAIM's Advanced Form Labeling article](https://webaim.org/techniques/forms/advanced) for more details.
+WAI-ARIA also enables some advanced form labelling techniques, beyond the classic {{htmlelement("label")}} element. We already talked about using the [`aria-label`](https://www.w3.org/TR/wai-aria-1.1/#aria-label) property to provide a label where we don't want the label to be visible to sighted users (see the [Signposts/Landmarks](#signpostslandmarks) section, above). There are some other labelling techniques that use other properties such as [`aria-labelledby`](https://www.w3.org/TR/wai-aria-1.1/#aria-labelledby) if you want to designate a non-`<label>` element as a label or label multiple form inputs with the same label, and [`aria-describedby`](https://www.w3.org/TR/wai-aria-1.1/#aria-describedby), if you want to associate other information with a form input and have it read out as well. See [WebAIM's Advanced Form Labeling article](https://webaim.org/techniques/forms/advanced) for more details.
 
 There are many other useful properties and states too, for indicating the status of form elements. For example, `aria-disabled="true"` can be used to indicate that a form field is disabled. Many browsers will just skip past disabled form fields, and they won't even be read out by screenreaders, but in some cases they will be perceived, so it is a good idea to include this attribute to let the screenreader know that a disabled input is in fact disabled.
 
@@ -339,7 +339,7 @@ function toggleMusician(bool) {
 
 #### Describing non-semantic buttons as buttons
 
-A few times in this course already, we've mentioned the native accessibility of (and the accessibility issues behind using other elements to fake) buttons, links, or form elements (see [UI controls](/en-US/docs/Learn/Accessibility/HTML#ui_controls) in the HTML accessibility article, and {{anch("Enhancing keyboard accessibility")}}, above). Basically, you can add keyboard accessibility back in without too much trouble in many cases, using `tabindex` and a bit of JavaScript.
+A few times in this course already, we've mentioned the native accessibility of (and the accessibility issues behind using other elements to fake) buttons, links, or form elements (see [UI controls](/en-US/docs/Learn/Accessibility/HTML#ui_controls) in the HTML accessibility article, and [Enhancing keyboard accessibility](#enhancing_keyboard_accessibility), above). Basically, you can add keyboard accessibility back in without too much trouble in many cases, using `tabindex` and a bit of JavaScript.
 
 But what about screenreaders? They still won't see the elements as buttons. If we test our [fake-div-buttons.html](https://mdn.github.io/learning-area/tools-testing/cross-browser-testing/accessibility/fake-div-buttons.html) example in a screenreader, our fake buttons will be reported using phrases like "Click me!, group", which is obviously confusing.
 

files/en-us/learn/accessibility/wai-aria_basics/test_your_skills_colon__wai-aria/index.md

@@ -15,7 +15,7 @@ This aim of this skill test is to assess whether you've understood our [WAI-ARIA
 
 > **Note:** You can try out solutions in the interactive editors below, however it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## WAI-ARIA 1
 

files/en-us/learn/css/building_blocks/a_cool_looking_box/index.md

@@ -44,7 +44,7 @@ To get this assessment started, you should:
 
 Alternatively, you could use a site like [JSBin](https://jsbin.com/) or [Glitch](https://glitch.com/) to do your assessment. You could paste the HTML and fill in the CSS into one of these online editors. If the online editor you are using doesn't have a separate CSS panel, feel free to put it in a `<style>` element in the head of the document.
 
-> **Note:** If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> **Note:** If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Project brief
 

files/en-us/learn/css/building_blocks/box_model_tasks/index.md

@@ -11,7 +11,7 @@ The aim of this task is to help you check your understanding of the CSS Box Mode
 
 > **Note:** You can try out solutions in the interactive editors below, however, it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## The Box Model One
 

files/en-us/learn/css/building_blocks/cascade_tasks/index.md

@@ -11,7 +11,7 @@ The aim of this task is to help you check your understanding of the universal pr
 
 > **Note:** You can try out solutions in the interactive editors below, however, it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Task One
 

files/en-us/learn/css/building_blocks/creating_fancy_letterheaded_paper/index.md

@@ -48,7 +48,7 @@ To get this assessment started, you should:
 
 Alternatively, you could use a site like [JSBin](https://jsbin.com/) or [Glitch](https://glitch.com/) to do your assessment. You could paste the HTML and fill in the CSS into one of these online editors. If the online editor you are using doesn't have a separate CSS panel, feel free to put it in a `<style>` element in the head of the document.
 
-> **Note:** If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> **Note:** If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Project brief
 

files/en-us/learn/css/building_blocks/fundamental_css_comprehension/index.md

@@ -45,7 +45,7 @@ To get this assessment started, you should:
 
 Alternatively, you could use a site like [JSBin](https://jsbin.com/) or [Glitch](https://glitch.com/) to do your assessment. You could paste the HTML and fill in the CSS into one of these online editors, and use [this URL](https://mdn.github.io/learning-area/css/introduction-to-css/fundamental-css-comprehension/chris.jpg) to point the `<img>` element to the image file. If the online editor you are using doesn't have a separate CSS panel, feel free to put it in a `<style>` element in the head of the document.
 
-> **Note:** If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> **Note:** If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Project brief
 

files/en-us/learn/css/building_blocks/images_tasks/index.md

@@ -11,7 +11,7 @@ The aim of this task is to help you check your understanding of some of the valu
 
 > **Note:** You can try out solutions in the interactive editors below, however, it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Task One
 

files/en-us/learn/css/building_blocks/overflow_tasks/index.md

@@ -11,7 +11,7 @@ The aim of these tasks is to help you check your understanding of overflow in CS
 
 > **Note:** You can try out solutions in the interactive editors below, however, it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Task One
 

files/en-us/learn/css/building_blocks/selectors/selectors_tasks/index.md

@@ -11,7 +11,7 @@ The aim of this task is to help you check your understanding of selectors in CSS
 
 > **Note:** You can try out solutions in the interactive editors below, however, it may be helpful to download the code and use an online tool such as [CodePen](https://codepen.io/), [jsFiddle](https://jsfiddle.net/), or [Glitch](https://glitch.com/) to work on the tasks.
 >
-> If you get stuck, then ask us for help — see the {{anch("Assessment or further help")}} section at the bottom of this page.
+> If you get stuck, then ask us for help — see the [Assessment or further help](#assessment_or_further_help) section at the bottom of this page.
 
 ## Selectors One