Merge pull request #11673 from jetthoughts/11671_describe_access_to_helpers_from_controller

Improve documentation for controller how to get included helpers

actionpack/lib/action_controller/metal/helpers.rb

@@ -5,7 +5,7 @@ module ActionController
   #
   # In addition to using the standard template helpers provided, creating custom helpers to
   # extract complicated logic or reusable functionality is strongly encouraged. By default, each controller
-  # will include all helpers.
+  # will include all helpers. These helpers are only accessible on the controller through <tt>.helpers</tt>
   #
   # In previous versions of \Rails the controller will include a helper whose
   # name matches that of the controller, e.g., <tt>MyController</tt> will automatically