feat: remove easy admin bundle, adopt admin theme

templates/admin/dashboard.html.twig

@@ -0,0 +1,10 @@
+{% extends 'layout_admin.html.twig' %}
+
+{% block content %}
+    <h1>
+        MyE&amp;P Admin
+    </h1>
+    <p>
+        Noch nicht wirklich was zu sehen hier...
+    </p>
+{% endblock %}