fix(bcd): explain features with unknown earliest release version

[gagan-bhullar-tech]

Summary

Fixes #11257

Problem

Explained in the linked issue

Solution

Renders the text

Yes
Full support (earliest supporting release version unknown)

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Screenshots

Before

After

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How did you test this change?

[caugner]

@gagan-bhullar-tech Could you please add before/after screenshots? 🙏

[gagan-bhullar-tech]

@caugner

Before

After

[caugner]

@danielhjacobs Could you please take another look? 🙏

[danielhjacobs]

I'm not actually able to display some yari pages properly right now and I'm not sure why. The CSS and JS files are being served as HTML:

The stylesheet http://localhost:3000/static/css/main.debc7a6f.css was not loaded because its MIME type, “text/html”, is not “text/css”.
Uncaught SyntaxError: expected expression, got '<'

[danielhjacobs]

Also worth noting, @queengooborg is making a concerted effort to remove all instances of true from the BCD, so this PR will only be useful for probably less than a month before that effort is finished.

There are 30 remaining files, all either webextensions.api or webextensions.manifest: https://github.com/search?q=repo%3Amdn%2Fbrowser-compat-data+%22%5C%22version_added%5C%22%3A+true%22&type=code (most were actually just updated, but some true values seem to have been missed).

[danielhjacobs]

Ah I see:

#4654

Unfortunately, many of the pages that reproduce this issue are there.

[danielhjacobs]

Tested http://localhost:3000/en-US/docs/Mozilla/Add-ons/WebExtensions/API/events#browser_compatibility and http://localhost:5042/en-US/docs/Mozilla/Add-ons/WebExtensions/manifest.json/externally_connectable#browser_compatibility (it had to be that URL, :3000 doesn't work for the manifest pages) and this seems to work, and the code seems fine.

[danielhjacobs]

For reference, 2 files are left that would be affected by this PR, and that will reduce to 0 over time:

1. https://github.com/mdn/browser-compat-data/blob/main/webextensions/api/commands.json - Chrome data, fixed by Update Chromium data for commands Web Extensions interface browser-compat-data#24263
2. https://github.com/mdn/browser-compat-data/blob/main/webextensions/manifest/commands.json - Chrome data, fixed by Update Chromium data for commands Web Extensions manifest property browser-compat-data#24293