Add escaping for doxygen

Many characters have special meaning and break formatting

Author: Earlopain

templates/include/prism/ast.h.erb

@@ -22,7 +22,7 @@
  */
 typedef enum pm_token_type {
 <%- tokens.each do |token| -%>
-    /** <%= token.comment %> */
+    /** <%= Prism::Template::Doxygen.escape(token.comment) %> */
     PM_TOKEN_<%= token.name %><%= " = #{token.value}" if token.value %>,
 
 <%- end -%>

templates/template.rb

@@ -49,6 +49,13 @@ def self.escape(value)
       end
     end
 
+    # This module contains methods for escaping characters in Doxygen comments.
+    module Doxygen
+      def self.escape(value)
+        value.gsub(/[\.*%!`#<>_+-]/, '\\\\\0')
+      end
+    end
+
     # A comment attached to a field or node.
     class ConfigComment
       attr_reader :value