[ruby/prism] [DOC] Stop rdoc from processing non-rdoc comments

https://github.com/ruby/prism/commit/de1faa1680

lib/prism/node_ext.rb

@@ -1,8 +1,10 @@
 # frozen_string_literal: true
 # :markup: markdown
 
+#--
 # Here we are reopening the prism module to provide methods on nodes that aren't
 # templated and are meant as convenience methods.
+#++
 module Prism
   class Node
     def deprecated(*replacements) # :nodoc:

prism/templates/template.rb

@@ -554,9 +554,11 @@ module Prism
             # :markup: markdown
 
             =begin
+            --
             This file is generated by the templates/template.rb script and should not be
             modified manually. See #{filepath}
             if you are looking to modify the template
+            ++
             =end
 
             HEADING