Add back 404 page video

Author: rlee80

404.html

@@ -9,6 +9,9 @@
                 <h2>Page not found :(</h2>
                 <p>The requested page could not be found.</p>
             </div>
+            <div>
+                <iframe class="embed-responsive-item" src="https://www.youtube.com/embed/t3otBjVZzT0?autoplay=1" frameborder="0" allowfullscreen></iframe>
+            </div>
         </div>
     </div>
 </div>