Fix title in gocam_app

Author: kimrutherford

gocam_app/templates/gocam_app/index.html

@@ -33,7 +33,7 @@ <h4>Links:</h4>
       </li>
     </ul>
 
-    <h4>Create a model from IDs:</h4>
+    <h4>Create a diagram from IDs:</h4>
 
     <form id="id-lookup" action="" method="post">
       {% csrf_token %}