Add Jai language

[funkkiy]

Description

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*.jai+ifx
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/Ivo-Balbaert/The_Way_to_Jai/tree/main
    • Sample license(s): Apache 2.0
  • I have included a syntax highlighting grammar: https://github.com/SogoCZE/Jails
  • I have added a color
    • Hex value: #AB8B4B
    • Rationale: Arbritrarily chosen: there is no official language logo, to my knowledge.
  • I have updated the heuristics to distinguish my language from others using the same extension: There is no extension conflict with any other languages, thus I haven't written a heuristic.

[funkkiy]

I had to fork the original grammar repository because it was picking up another .json file as the syntax.
Closes #6631.

Edit: Now using the Jails syntax as it is more up-to-date with current language features.