r-ts-mode

Emacs mode for R (treesit)

THis is very much proof of concept code. So far there is basic support for:

1. Navigation to beg/end of defuns (C-M-a and C-M-e).
2. Imenu support for functions.
3. Font lock.
4. Indentation is working, but v. primitive.

See test code in the file r-ts-examples.R