Add Godot Resource Language

[lildude]

Description

project.godot, .tres and .tscn files form part of many GoDot apps and are really popular on GitHub.

I've stuck with the same colour as used by GDScript as they're related so may as well share the same colour of: #355570

Fixes #6060

Checklist:

• I am adding a new language.
  • The new extension is used in hundreds of repositories on github.com
    • Search results for each extension:
      • .gdns
      • .gdnlib
      • .tscn
      • .tres
      • project.godot
  • I have included a real-world usage sample for all extensions added in this PR:
    • Sample source(s):
      • .tscn and .tres https://github.com/Orama-Interactive/Pixelorama
      • project.godot
      • .gdns, .gdnlib https://github.com/godot-rust/gdnative
    • Sample license(s): all covered by MIT
  • I have included a syntax highlighting grammar: [URL to grammar repo]
  • I have included a change to the heuristics to distinguish my language from others using the same extension.
    • Not needed as they're unique

[aaronfranke]

This is completely and totally wrong.

• .tres and .tscn files are specific to Godot Engine, not to the GDScript language. Games using C# in Godot with no GDScript will still have .tres and .tscn files.

• The syntax highlighting needed for .tres and .tscn is completely different from GDScript.

[lildude]

@aaronfranke I was kinda expecting a comment like this as I know nothing about Godot and was winging it 😁

• .tres and .tscn files are specific to Godot Engine, not to the GDScript language. Games using C# in Godot with no GDScript will still have .tres and .tscn files.

The issue here is we can't add "Godot Engine" or similar as its own language to Linguist as it isn't a language, it's framework, hence I chose GDScript which brings me to your next point:

• The syntax highlighting needed for .tres and .tscn is completely different from GDScript.

I was motivated to add these files to GDScript as that's what the Godot docs use for the code blocks (see the page source) and things seem to look OK.

Now I'm looking at it again, and looking at the grammar itself, would it make more sense to add a new "GDResource" data language for these extensions? That's what VSCode identifies these file as when I open them with https://github.com/godotengine/godot-vscode-plugin/ installed (which we use for the GDScript syntax highlighting).

[aaronfranke]

@lildude Yes, these files use Godot's Resource / ConfigFile format, including project.godot, *.tres, and *.tscn.

Note that we want to avoid marking these files as code (we should use Linguist type: data).

[Alhadis]

LGTM.