Change the slug for the theme.json doc to avoid conflicts

[ndiego]

It turns out that each doc slug needs to be unique. A new theme.json doc was created in #57289 and the slug was simply theme-json, which already existed. Therefore, the new doc was not synced to the Handbook.

This PR modifies the slug to theme-json-configurations, thus making it unique.

Edit: Following the comment below, I have updated the approach in this PR to instead change the slug of the Global Settings & Styles doc. While updating that doc, I also removed an unnecessary TOC.

Warning

I have also created the redirect PR here: WordPress/wporg-developer#457. This PR should be merged at the same time the redirect PR is put in place.

[t-hamano]

I feel it's better if the slug is based on the page title. The title of the page added in #57289 is "Global Settings & Styles (theme.json)", but the page title and slug are theme-json. How about changing this to global-settings-and-styles to avoid duplication?

In other words, the classification is as follows.

Page Title	How-to Guides > Themes > Global Settings & Styles (theme.json)	How-to Guides > Curating the Editor Experience > theme.json
Slug	global-settings-and-styles	theme.json
Source	../docs/how-to-guides/themes/global-settings-and-styles.md	../docs/how-to-guides/curating-the-editor-experience/theme-json.md

Reference: Similar page in the theme handbook

[ndiego]

I feel it's better if the slug is based on the page title. The title of the page added in #57289 is "Global Settings & Styles (theme.json)", but the page title and slug are theme-json. How about changing this to global-settings-and-styles to avoid duplication?

Yeah, I do like that better. Good call @t-hamano. This will require a new redirect to be put in place. I will get this PR and the redirect PR put together today.

[ndiego]

@t-hamano I have updated this PR based on your suggested approach. I have also created the redirect PR here: WordPress/wporg-developer#457. This PR should be merged at the same time the redirect PR is put in place.

[t-hamano]

I've made a few suggestions regarding links, and overall things seem fine 👍

In addition to this, I suspect that the link below is also not working properly.

gutenberg/docs/how-to-guides/themes/theme-support.md

Line 437 in 4ca8767

Link support has been made stable as part of WordPress 5.8. It's `false` by default and themes can enable it via the [theme.json file](./theme-json.md):

Perhaps /docs/how-to-guides/curating-the-editor-experience/theme-json.md rather than ./theme-json.md?

[ndiego]

Perhaps /docs/how-to-guides/curating-the-editor-experience/theme-json.md rather than ./theme-json.md?

Good catch, missed that one. All updated.

[t-hamano]

LGTM 🚀