Add support for Ink

[benthicmaw]

Adding support for Inkle's Ink scripting language, used for writing Interactive Fiction.

Description

• Added TextMate format language grammar.
• Added samples (MIT licensed), obtained from the official Inky repo here.

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%3Aink+INCLUDE&type=Code
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • All samples obtained from here
    • Sample license(s):
      • MIT License at bottom of README.MD
  • I have included a syntax highlighting grammar: https://github-lightshow.herokuapp.com/
    • theintercept.ink (included in samples)
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

We really don't need this many samples, especially when most of the content of them is a comment.

Please reduce the number of samples to two or three that are most representative of the general usage of the language.

You probably want to add a color too else the language will fallback to a very boring grey

[lildude]

I've cleaned up the samples and resolved all issues - sorry for the noise - so this is now ready for merging as the popularity looks good now.

[benthicmaw]

Great, thanks a lot @lildude!