Add support for Browserslist

[voskresla]

Description

This PR add support for Browserslist configs.

Syntax highlighting based on https://github.com/browserslist/browserslist-vscode.
cc @ai

Checklist:

• I am adding a new language.
  • The extension of the new language is used in hundreds of repositories on GitHub.com
    • .browserslistrc: ~360,347 results
    • browserslist: ~826,669 results
  • I have included a real-world usage sample for all extensions added in this PR:
    • Source: browserslist/browserslist-vscode
    • License: MIT
  • I have included a syntax highlighting grammar:
    • Preview
    • MIT-licensed
  • I have updated the heuristics to distinguish my language from others using the same extension.

[ai]

Adding Browserslist config highlighting is important because it is default way to specify target browsers in Autoprefixer and Babel and it is already used in 350K public repositories.

[Alhadis]

Usage checks out (I happen to be familiar with the format, so I'm skipping the usual sample harvest routine). Just a small nit to correct and we should be good to go. 👍

[Alhadis]

@voskresla You might want to set core.ignorecase globally so it's configured for all future projects:

$ git config --global core.ignorecase false

Or add to your ~/.gitconfig file:

[core]
	ignorecase = false

The --local switch sets a config setting for one particular repository directory only (stored in .git/config). So it won't persist across other projects, including future checkouts of Linguist.

[voskresla]

)

[Alhadis]

LGTM. 👍

@lildude, I say we .

[wspwebben]

@ai mentioned browserslist config name is deprecated, does it makes sense to drop it from samples? We should keep support for existing configs, so it's only about example file.

[Alhadis]

@wspwebben We don't judge formats on their deprecation– or recommendation-status, only their real-world distribution. Discouraging the use of a filename won't change the fact there are over a million files on GitHub using that particular format and filename.

[wspwebben]

@wspwebben We don't judge formats on their deprecation– or recommendation-status, only their real-world distribution. Discouraging the use of a filename won't change the fact there are over a million files on GitHub using that particular format and filename.

That's why we should keep support for that format in configs, so syntax highlight would still work for these files, but there's no need to keep that format as an example in samples

[Alhadis]

but there's no need to keep that format as an example in samples

There is. The samples directory isn't for human consumption—it's to train our Bayesian classifier, which disambiguates files based on the frequency of certain tokens. The more samples Linguist has, the more accurate its predictions are.

[wspwebben]

Got it, thank you for clarification :D

[Alhadis]

No problem! 😉 That's also the reason we prefer "real-world" samples instead of just "Hello, world" examples, BTW:—they need to be an accurate rendition of the sort of files Linguist will encounter in-the-wild after it starts indexing the new language.

[lildude]

LGTM.

This won't go live on GitHub.com until a new release is made which I won't be able to do until mid-to-late January at the earliest.