Huh, unfortunately, these files are made of actual s-expressions, just like normal Scheme or Lisp code.

Possibly the idiosynchratic use of symbols starting with @, including sometimes at the top level, can help?

If that doesn't work out, I guess https://github.com/github-linguist/linguist/blob/master/docs/overrides.md might still help?

I think it would suffice to simply add query as an alias for scheme, so editors with better support (Neovim) can leverage that while still getting basic scheme syntax highlighting on Github.

(To be clear, the main goal here is codeblock injections in markdown.)

If you want to go the extra mile and this is possible for linguist, you can distinguish by file path: any **/queries/*/*.scm file is very likely a query. (This is how Neovim decides, but the convention is of course global across the tree-sitter ecosystem.)