Basic splash page set up

Just getting the bare minimum styles and templates created and rendering
properly to have a simple splash going.

config/bundles.php

@@ -2,4 +2,7 @@
 
 return [
     Symfony\Bundle\FrameworkBundle\FrameworkBundle::class => ['all' => true],
+    Sensio\Bundle\FrameworkExtraBundle\SensioFrameworkExtraBundle::class => ['all' => true],
+    Symfony\Bundle\TwigBundle\TwigBundle::class => ['all' => true],
+    Twig\Extra\TwigExtraBundle\TwigExtraBundle::class => ['all' => true],
 ];