Added more config formats

Author: javiereguiluz

session/database.rst

@@ -46,14 +46,34 @@ First, define a Symfony service for the connection to the Redis server:
 Now pass this Redis connection as an argument of the service associated to the
 :class:`Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler`:
 
-.. code-block:: yaml
+.. configuration-block::
 
-    # config/services.yaml
-    services:
-        # ...
-        Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler:
-            arguments:
-                - '@Redis'
+    .. code-block:: yaml
+
+        # config/services.yaml
+        services:
+            # ...
+            Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler:
+                arguments:
+                    - '@Redis'
+
+    .. code-block:: xml
+
+        <!-- config/services.xml -->
+        <services>
+            <service id="Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler">
+                <argument type="service" id="Redis"/>
+            </service>
+        </services>
+
+    .. code-block:: php
+
+        // config/services.php
+        use Symfony\Component\HttpFoundation\Session\Storage\Handler\RedisSessionHandler;
+
+        $container
+            ->register(RedisSessionHandler::class)
+            ->addArgument(new Reference('Redis'));
 
 Next, use the :ref:`handler_id <config-framework-session-handler-id>`
 configuration option to tell Symfony to use this service as the session handler: