Add support for Caddyfile

[willnorris]

Add support for Caddyfile, one of the main configuration formats of the Caddy web server.

Checklist:

• I am adding a new language.
  • The extension of the new language is used in hundreds of repositories on GitHub.com.
    • Search results for each extension:
      • https://github.com/search?type=code&q=NOT+is%3Afork+path%3A**%2FCaddyfile+NOT+org%3Acaddyserver
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/caddyserver/caddy/blob/master/caddytest/integration/caddyfile_adapt/acme_server_lifetime.caddyfiletest
      • https://github.com/caddyserver/caddy/blob/master/caddytest/integration/caddyfile_adapt/reverse_proxy_handle_response.caddyfiletest
    • Sample license(s): Apache 2.0
  • I have included a syntax highlighting grammar: [URL to grammar repo]
  • I have added a color
    • Hex value: #22b638
    • Rationale: Taken from the green in the caddy logo
  • I have updated the heuristics to distinguish my language from others using the same extension.

/cc @mholt as fyi

[mholt]

Ohh this would be awesome for so many users! Thank you Will.

[lildude]

LGTM. Thanks.

Note: this PR will not be merged until close to when the next release is made. See here for more details.

[wooorm]

This seems to be the first scope with a capital letter. Is that intentional? Given that all others use lowercase, shouldn’t this too?

[lildude]

This seems to be the first scope with a capital letter. Is that intentional? Given that all others use lowercase, shouldn’t this too?

You'd need to ask the grammar maintainers as that's how it is defined in the grammar and is where we get it from.

I don't believe there is a requirement that only lowercase letters be used; it's probably just common practise. Either way, GitHub's syntax highlighting doesn't have a problem with the case used for the scope name

[wooorm]

/cc @matthewpi

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Either way, GitHub's syntax highlighting doesn't have a problem with the case used for the scope name

Are you sure? I was wondering about this too, but as the GH site is behind, I can’t confirm it.
I wonder because there’s also a source.pov-ray sdl here, which turns into two separate classes on GH web.
In my case, scopes turn into file names, and given that case-sensitivity between file systems varies, I foresee it might get fragile.

[lildude]

Are you sure?

Yes, in as much as Caddyfiles are getting syntax highlighting on GitHub, and they're only getting it because the syntax highlighter has correctly associated source.Caddyfile with the Caddyfile language and associated grammar. Any problems with that highlighting of part of these files is entirely up to the grammar.