Use Python syntax highlighting for Ren'Py scripts.

Ren'Py is a very popular Python visual novel engine, which has it's own "coding language" (even GitHub shows it as a separate language) and it's own file extension.
Generally Python syntax highlighting works for the Ren'Py language.

data/plugins/language_python.lua

@@ -2,7 +2,7 @@
 local syntax = require "core.syntax"
 
 syntax.add {
-  files = { "%.py$", "%.pyw$" },
+  files = { "%.py$", "%.pyw$", "%.rpy$" },
   headers = "^#!.*[ /]python",
   comment = "#",
   patterns = {