minor #5262 Update Routes in the Getting Started documentation (BT643)

This PR was merged into the 2.3 branch.

Discussion
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Update Routes in the Getting Started documentation

The @routes in the  "Actions and Controllers" and "Routes" sections of the Getting Started documentation are outdated it seems.

I have just created a new project and it wasn't quite right. Of course you can still make sense of it but needs correcting.

Commits
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7d52ec8 Update the_big_picture.rst
b1e3b31 Update Routes in the Getting Started documentation

Author: wouterj

quick_tour/the_big_picture.rst

@@ -156,7 +156,7 @@ because that will be explained in the next section)::
     class DefaultController extends Controller
     {
         /**
-         * @Route("/", name="homepage")
+         * @Route("/app/example", name="homepage")
          */
         public function indexAction()
         {
@@ -198,7 +198,7 @@ at the three lines of code above the ``indexAction`` method::
     class DefaultController extends Controller
     {
         /**
-         * @Route("/", name="homepage")
+         * @Route("/app/example", name="homepage")
          */
         public function indexAction()
         {
@@ -219,7 +219,7 @@ the application homepage. The second value of ``@Route()`` (e.g.
 ``name="homepage"``) is optional and sets the name of this route. For now
 this name is not needed, but later it'll be useful for linking pages.
 
-Considering all this, the ``@Route("/", name="homepage")`` annotation creates
+Considering all this, the ``@Route("/app/example", name="homepage")`` annotation creates
 a new route called ``homepage`` which makes Symfony execute the ``index``
 action of the ``Default`` controller when the user browses the ``/`` path
 of the application.