Add Language: Imba

[familyfriendlymikey]

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?q=extension%3Aimba+NOT+nothack&type=Code
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/imba/game-of-life
    • Sample license(s): MIT
  • I have included a syntax highlighting grammar: https://github.com/imba/imba-linguist-grammar
  • I have updated the heuristics to distinguish my language from others using the same extension. (There is no other imba extension.)

[familyfriendlymikey]

Thank you very much!

[MystPi]

Just out of curiosity: when will this get released?

[lildude]

I'm aiming for the next week or two, probably next week sometime.