add language ron

[VuiMuich]

This adds language support for 'ron' as suggested in matrix chat by using the rust grammar and queries.
According to @the-M̀ikedavis there is a bug preventing the rust queries to be used direktly, therefore I symlinked runtime/queries/ron to ./rust as workaround. Not sure though, if this also works on windows.

[the-mikedavis]

Actually I forgot about the inherits feature for queries. Instead of symlinking, let's use a file that just says

; inherits: rust

for runtime/queries/ron/highlights.scm plus the same for the injections.scm and indents.scm.

To clear up the CI, you'll need to run cargo xtask docgen and commit the changes.

[the-mikedavis]

Looks good, thanks!

[VuiMuich]

Thanks for all the hints, I merely put the pieces of this jigsaw 🧩 together.