Add Hare

[MalloryA]

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*.ha+(use%20OR%20fn)
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://git.sr.ht/~sircmpwn/hare/tree/master/item/bytes/contains.ha
      • https://git.sr.ht/~sircmpwn/hare/tree/master/item/fmt/iter.ha
      • https://git.sr.ht/~sircmpwn/hare/tree/master/item/fs/types.ha
    • Sample license(s):
      • MPL-2.0
  • I have included a syntax highlighting grammar: I don't think Hare has this yet
  • I have added a color
    • Hex value: #9d7424
    • Rationale: Hare doesn't have an official color, but hares are brown so I chose a brown
  • I have updated the heuristics to distinguish my language from others using the same extension. There are no other languages in lib/linguist/languages.yml with this extension.