Add reformat-files:css script

[simison]

Adds reformat-files:css script that runs stylelint --fix on files.

There's this note in the docs:

It's an experimental feature. It currently does not respect special comments for disabling stylelint within sources (e. g. /* stylelint-disable */). Autofixing will be applied regardless of these comments.

If you're using both these special comments and autofixing, please run stylelint twice as a temporary solution. On the first run, some violations could be missed, or some violations might be reported incorrectly.

Solution might be not run this together with reformat-files command and let folks run this only manually.

Changes proposed in this Pull Request

• Add new reformat-files:css script which always exists with 0 — otherwise if there are errors left, --fix will exit with 2 and make it seem like reformat-files failed. -c in reformat-files is meant to let reformat-files:js finish even if :css would exit with non-0 earlier, so I'm fine also changing it to throw an error at the end.
• Add .json to config file so that it'll get run through Prettier (docs about .json support)
• Run some files through it.

Testing instructions

Run:

• npm run reformat-files
  • Observe reformat-files:js finish even if :css finishes earlier
  • Linter throws some errors/warnings about stuff it cannot autofix but doesn't fail the NPM script with error.
  • A bunch of files have changed (happy to include these in the PR, but I made a separate: Fix stylelint errors in scss files #32386)
• npm run reformat-files:css

[matticbot]

Test live: https://calypso.live/?branch=update/reformat-files-css

[matticbot]

This PR does not affect the size of JS and CSS bundles shipped to the user's browser.

Generated by performance advisor bot at iscalypsofastyet.com.

[blowery]

rebased this and resolved the conflicts in package.json::scripts

[simison]

Rebased. Still not sure if this is helpful or too risky (see the warning I added in description).

This would be handy if we'd switch e.g. to this from our custom Stylelint config:

{
	"extends": "stylelint-config-wordpress/scss"
}

[scinos]

This PR has been open for a while. Is it still relevant?

[github-actions]

This PR has been marked as stale due to lack of activity within the last 30 days.

[simison]

Autofixer might be now safe enough to use: stylelint/stylelint#2643

[simison]

Considered closing this, but checked with Team Calypso (p1623060403258400-slack-team-calypso) and I think we can keep open until someone picks the stylelint work at some point. This will work as a good starting off point:

fine to keep open by me. Running stylelint as part of CI is something I’d like to do eventually

[simison]

@noahtallen is this PR needed for the recent stylelint work or shall I close? Feel free to just hit close button yourself! :-)

[noahtallen]

Yeah, I think it's worth closing!

[noahtallen]

I didn't add a reformat files script, but that'd be incredibly easy to add if we need it. And just adding --fix to yarn lint:css is very easy too