Major mode for TypeSpec using tree-sitter.

This mode uses tree-sitter-typespec for syntax rules.

• (treesit-available-p) -> t
• (treesit-library-abi-version) -> support 15

I have a PR out to treesit-auto and will use that when it is imported. Or run the (typespec-ts-another-mode-grammar-install) only the first time.

lsp-mode already supports typespec. TypeSpec - LSP Mode - LSP support for Emacs

There is no relationship whatsoever. I started writing this software in November 2024, became roughly practical in December, and when I decided to register it with melpa with a heavy heart in March, I noticed that the package was registered under the name typespec-ts-mode. It seems that typespec-ts-mode was developed around January. I have no ill feelings towards typespec-ts-mode at all. Before tree-sitter, it would have been a bad idea to split the package because it would have distributed development resources, but this is like the main body of tree-sitter's main rules, so you don't have to worry about it too much. However, I also went through the trouble of writing up the package besides improving tree-sitter itself, so I'm going to release it as such.