docs: text decoration

Also remove add() in examples becase it is not recommended.

Author: kenjis

user_guide_src/source/incoming/routing.rst

@@ -390,7 +390,7 @@ available from the command line:
 Global Options
 ==============
 
-All of the methods for creating a route (add, get, post, :doc:`resource <restful>` etc) can take an array of options that
+All of the methods for creating a route (``get()``, ``post()``, :doc:`resource() <restful>` etc) can take an array of options that
 can modify the generated routes, or further restrict them. The ``$options`` array is always the last parameter:
 
 .. literalinclude:: routing/033.php