add extensions for nim files

[timotheecour]

what's changing

this fixes https://forum.nim-lang.org/t/4307: syntax highlight of nims, nim.cfg, nimble files broken on github

as reported there, these don't syntax highlight correctly:

• https://github.com/kaushalmodi/hello_musl/blob/master/config.nims
• https://github.com/nim-lang/Nim/blob/devel/tests/deps/zip-0.2.1/zip.nimble
• https://github.com/nim-lang/Nim/blob/devel/config/nim.cfg

Checklist:

• I am associating a language with a new file extension.
  • The new extension is used in hundreds of repositories on GitHub.com
    • Search results for each extension:
      • https://github.com/search?utf8=%E2%9C%93&type=Code&ref=searchresults&q=extension%3A.nimble+skipDirs+NOT+nothack
      • https://github.com/search?utf8=%E2%9C%93&type=Code&ref=searchresults&q=extension%3A.nims+defined+NOT+nothack
      • https://github.com/search?q=filename%3Anim.cfg+path&type=Code
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/kaushalmodi/hello_musl/blob/master/config.nims
      • https://github.com/nim-lang/Nim/blob/devel/tests/deps/zip-0.2.1/zip.nimble
      • https://github.com/nim-lang/Nim/blob/devel/config/nim.cfg
    • Sample license(s):
      • https://github.com/yglukhov/nimx/blob/master/LICENSE
  • I have included a change to the heuristics to distinguish my language from others using the same extension.

[alehander92]

looks ok, is .nimrod still used?

[timotheecour]

only old projects

[pchaigno]

Thanks for your contribution!

I left a few comments inline regarding new extensions and filenames. Could you also add the sample files (including sample files for new filenames) under samples/Nims/?

For other reviewers, here what I found for extension/filename:

• extension:nimble, 1776 repos, 644 users
• extension:nims defined, 52 files
• filename:nim.cfg, 694 repos, 362 users
• filename:config.nims, 146 files

[timotheecour]

@pchaigno

Could you also add the sample files (including sample files for new filenames) under samples/Nims/

done

• I'm assuming you meant samples/Nim/, not samples/Nims/

• /cc @Araq for these samples, I took some files from Nim repo, let me know if that's not ok (I added from .url... at top-level for each such file)

• @pchaigno this should be added to readme (the fact we need to add to samples), as well as to pull request template (IIRC it wasn't mentioned?)

[kaushalmodi]

Looks great to me.

[Araq]

@timotheecour That's totally fine.

[timotheecour]

/cc @pchaigno friendly ping; anything else that needs changing?

[timotheecour]

/cc @pchaigno @Alhadis @lildude
ping (no feedback, good to merge?)

[pchaigno]

• I'm assuming you meant samples/Nim/, not samples/Nims/

Yes, sorry.

• @pchaigno this should be added to readme (the fact we need to add to samples), as well as to pull request template (IIRC it wasn't mentioned?)

It is mentioned in the contribution guidelines. I'll change the PR template to explicitly mention the directory.

[pchaigno]

Sorry for the delay @timotheecour. I wanted to recheck the usage.

Two comments to address below, but after that, I'd say we're good to merge!

[timotheecour]

@pchaigno PTAL

[pchaigno]

Thanks for your time and contribution @timotheecour!

[lildude]

LGTM and welcome to Linguist. Thanks for your contribution.

[timotheecour]

@pchaigno

not sure I'm understanding the result:
https://github.com/github/linguist/search?q=nim&unscoped_q=nim

• samples/Nim/config.nims
  is unclassified

• samples/Nim/nimfix.nim.cfg
  is classified as INI, not nim

• likewise with samples/Nim/filenames/nim.cfg

• https://github.com/github/linguist/search?q=skipDirs&unscoped_q=skipDirs shows samples/Nim/zip.nimble is unclassified

[pchaigno]

@timotheecour These changes will only apply once a new release of Linguist is cut.