* etc/NEWS: Mention the new mode.
* lisp/progmodes/ruby-ts-mode.el: New file.
* test/lisp/progmodes/ruby-ts-mode-tests.el: New file.
* lisp/progmodes/eglot.el (eglot-server-programs):
Add ruby-ts-mode to the Ruby entry.
Co-authored-by: Dmitry Gutov <dgutov@yandex.ru>