Add *.ron syntax mapping

Add a mapping to use `Rust` for rusty object notation, identified by `.ron` extension. See [#2427](https://github.com/sharkdp/bat/issues/2427).

CHANGELOG.md

@@ -17,6 +17,7 @@
 - Associate `Containerfile` with `Dockerfile` syntax, see #2606 (@einfachIrgendwer0815)
 - Replaced quotes with double quotes so fzf integration example script works on windows and linux. see #2095 (@johnmatthiggins)
 - Associate `ksh` files with `bash` syntax, see #2633 (@johnmatthiggins)
+- Associate `ron` files with `rust` syntax, see #2427 (@YeungOnion)
 
 ## Themes