Changes the default binary path in command samples

The console file is located in the bin folder and not in the app folder.

Resources/doc/reference/installation.rst

@@ -134,13 +134,13 @@ Now, install the assets from the bundles:
 
 .. code-block:: bash
 
-    $ php app/console assets:install
+    $ php bin/console assets:install
 
 Usually, when installing new bundles, it is a good practice to also delete your cache:
 
 .. code-block:: bash
 
-    $ php app/console cache:clear
+    $ php bin/console cache:clear
 
 At this point, your Symfony installation should be fully functional, with no errors
 showing up from SonataAdminBundle or its dependencies. SonataAdminBundle is installed