Update routing.rst

Added a note about the config example using a controller as a service and explained how you can also use a controller with a fully qualified class name.

Author: mediamonks-robert

book/routing.rst

@@ -332,6 +332,15 @@ Notice that ``enabled: true`` is no longer present. It's only required if no
 other configuration parameter is provided. The router is automatically enabled
 as soon as you add any other configuration to the ``dynamic`` entry.
 
+.. note::
+
+    This example uses a controller which is defined as a service. You can also
+    configure a controller by using a fully qualified class name:
+    ``CmfContentBundle:Content:index``.
+    
+    For more information on using controllers as a service read cook book 
+    section `How to Define Controllers as Services`_
+
 .. note::
 
     Internally, the routing component maps these configuration options to
@@ -529,3 +538,4 @@ For more information on the Routing component of Symfony CMF, please refer to:
 .. _`Doctrine ORM`: http://www.doctrine-project.org/projects/orm.html
 .. _`PHPCR-ODM`: http://www.doctrine-project.org/projects/phpcr-odm.html
 .. _`Routing`: http://symfony.com/doc/current/components/routing/introduction.html
+.. _`How to Define Controllers as Services`: http://symfony.com/doc/current/cookbook/controller/service.html