Add Rey programming language support

[IMisbahk]

Adds support for the Rey programming language with the .rey extension.

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*.rey+language
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • https://github.com/rey-language/rey
    • Sample license(s):
      • MIT
  • I have included a syntax highlighting grammar: [URL to grammar repo]
  • I have added a color
    • Hex value: #ff9361
    • Rationale: Selected for high contrast and clear visual distinction in GitHub’s language statistics.
  • I have updated the heuristics to distinguish my language from others using the same extension.

[lildude]

This PR is invalid. Please follow the instructions in the CONTRIBUTING.md file.