docs: Update extension-loading links and copyright date range

Closes #275, Closes #155

LICENSE

@@ -1,7 +1,7 @@
 Copyright © 2012 IBM Corp.
 Copyright © 2013-2016 The Paciello Group
 Copyright © 2016 Steve Faulkner
-Copyright © 2016-2018 Matthew Tylee Atkinson
+Copyright © 2016-2019 Matthew Tylee Atkinson
 
 Permission is hereby granted, free of charge, to any person obtaining a copy
 of this software and associated documentation files (the "Software"), to deal

README.md

@@ -118,9 +118,9 @@ You can build and run the current code locally as follows.
 
 4.  To load and use the extension locally in your browser...
     -   **Firefox:** either:
-        -   use [Mozilla's instructions on temporarily loading extensions from disk](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Packaging_and_installation#Loading_from_disk), or
+        -   use [Mozilla's instructions on temporarily loading extensions from disk](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Packaging_and_installation), or
         -   if you have [`web-ext`](https://developer.mozilla.org/en-US/Add-ons/WebExtensions/Getting_started_with_web-ext) installed, issue `npm run start:firefox` to open Firefox with Landmarks loaded. It will keep itself up-to-date when you re-build.
-    -   **Chrome:** follow [Google's instructions on loading the extension](https://developer.chrome.com/extensions/getstarted#unpacked).
+    -   **Chrome:** follow [Google's instructions on loading the extension](https://developer.chrome.com/extensions/getstarted#manifest).
     -   **Opera:** refer to [Testing and Debugging](https://dev.opera.com/extensions/testing/).
 
 Some further info on the test/build process: