Document why Basis columns are a, b, and c

[fpdotmonkey]

Why Basis doesn't follow Godot's column name convention came up in Discord, and the reasoning was fairly buried in code reviews and commits in other projects, so I'm sharing the knowledge with API users.

The explanation here is lifted directly from godot-rust/gdnative@16aa18e

[GodotRust]

API docs are being generated and will be shortly available at: https://godot-rust.github.io/docs/gdext/pr-776

[Bromeon]

Thanks a lot, this is worded much better than I could have 💪

Maybe we could also mention this for the transform types? Not copy-paste but link to the Basis explanation...

• https://godot-rust.github.io/docs/gdext/pr-776/godot/builtin/struct.Transform2D.html
• https://godot-rust.github.io/docs/gdext/pr-776/godot/builtin/struct.Transform3D.html
  • the 3D one currently has no such API, but it mentions a, b and c

[fpdotmonkey]

Thanks a lot, this is worded much better than I could have 💪

Appreciate it, though it's mostly copy-pasted from a commit you wrote. Anyway, made changes to the Transforms.