bug #33510 Minor tweaks to the welcome page (yceruto, javiereguiluz)

This PR was merged into the 4.4 branch.

Discussion
----------

Minor tweaks to the welcome page

| Q             | A
| ------------- | ---
| Branch?       | 4.4
| Bug fix?      | yes
| New feature?  | no
| BC breaks?    | no
| Deprecations? | no
| Tests pass?   | yes
| Fixed tickets | https://github.com/symfony/symfony/pull/33189#issuecomment-529177310
| License       | MIT
| Doc PR        | -

/cc @fabpot

Commits
-------

acd50615e7 Some styling tweaks
ddffc972a8 minor tweaks to the welcome page

src/Symfony/Component/HttpKernel/EventListener/RouterListener.php

@@ -164,11 +164,11 @@ class RouterListener implements EventSubscriberInterface
     private function createWelcomeResponse()
     {
         $version = Kernel::VERSION;
-        $baseDir = realpath($this->projectDir).\DIRECTORY_SEPARATOR;
+        $projectDir = realpath($this->projectDir).\DIRECTORY_SEPARATOR;
         $docVersion = substr(Kernel::VERSION, 0, 3);
 
         ob_start();
-        include __DIR__.'/../Resources/welcome.html.php';
+        include \dirname(__DIR__).'/Resources/welcome.html.php';
 
         return new Response(ob_get_clean(), Response::HTTP_NOT_FOUND);
     }