submenu generation implemented

web/pages/err/notfound.html

@@ -1,4 +1,5 @@
 <div class="bg-red-100 border-l-4 border-red-500 text-red-700 p-4" role="alert"> 
   <p class="font-bold">404 - Not found</p>
   <p>I have no memory of <?= escape($page) ?></p>
+  <img src="https://pictshare.net/4s9gi3.gif" alt="Gandalf: I have no memory of this place"/>
 </div>