minor symfony#9983 [Routing] do not install SensioFrameworkExtraBundle (Tobion, javiereguiluz)

This PR was merged into the 4.0 branch.

Discussion
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[Routing] do not install SensioFrameworkExtraBundle

The routing annotations of SensioFrameworkExtraBundle are deprecate since sensiolabs/SensioFrameworkExtraBundle#562
Also the example code in this documentation does not use SensioFrameworkExtraBundle at all but the core annotation as it should be. So installing the SensioFrameworkExtraBundle is pointless.

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c98babf Reword
6119b67 [Routing] do not install SensioFrameworkExtraBundle

Author: javiereguiluz

routing.rst

@@ -20,15 +20,19 @@ the change is simple.
 Creating Routes
 ---------------
 
-First, add support for annotations via the SensioFrameworkExtraBundle:
+A *route* is a map from a URL path to a controller. Suppose you want one route that
+matches ``/blog`` exactly and another more dynamic route that can match *any* URL
+like ``/blog/my-post`` or ``/blog/all-about-symfony``.
+
+Routes can be configured in YAML, XML and PHP. All formats provide the same
+features and performance, so choose the one you prefer. If you choose PHP
+annotations, run this command once in your app to add support for them:
 
 .. code-block:: terminal
 
-    $ composer require sensio/framework-extra-bundle
+    $ composer require annotations
 
-A *route* is a map from a URL path to a controller. Suppose you want one route that
-matches ``/blog`` exactly and another more dynamic route that can match *any* URL
-like ``/blog/my-post`` or ``/blog/all-about-symfony``:
+Now you can configure the routes:
 
 .. configuration-block::