Stylelint v14 Compatibility

[gfyoung]

Updates will also supersede the following PRs:

Closes: #195
Closes: #196

[stof]

Not having changes to use the new customSyntax option of stylelint looks suspicious to me.

[gfyoung]

Given that this repository is pretty much a configuration of existing rules, I don't see where it would be needed.

[stof]

Well, in stylelint 14, stylelint does not support parsing scss files if the config does not configure the customSyntax (see the migration guide).
and the config in this repository does not extend the one from stylelint-config-recommended-scss that would do it already, so it needs to provide that config, like this: https://github.com/stylelint-scss/stylelint-config-recommended-scss/blob/d373c8728cd130a7635173f19ce3bedf55eb9178/index.js#L5

[gfyoung]

True, but I would expect that the end user configures customSyntax in their .stylelintrc file.

I generally would not rely on the library to do that for me.

[stof]

Well, this config cannot be used without it. So why would it force the user to do it themselves ? That's the opposite of reusable configs.

[stof]

And having the config specific for a syntax specify that customSyntax is the official stylelint recommendation for config authors (which is why stylelint-config-recommended-scss does it)

[gfyoung]

Fair enough. Pushed a commit to address.

[bjankord]

This looks good to me, all tests pass. Thanks for the PR @gfyoung and thanks for the discussion @stof

The node 10 tests failing is expected since we're dropping that from the engines list. I'll work on updating the GitHub Actions to no longer run tests on node 10. I'll plan on getting a new major version for this repo cut soon.

[bjankord]

This has been released in v9.0.0. I also added the hacktoberfest topic to this repo, so if you are participating in that, you should get credit for this PR. Thanks again for the contribution @gfyoung and for the code review @stof!