Update custom.html

apps/schoolCalendar/custom.html

@@ -7,6 +7,7 @@
     <p>One you have created your events, Click <button id="upload" class="btn btn-primary">Upload</button></p>
     <p>All day events are not supported. A feature that lets you get the calendar from your watch will be added in a future update.</p>
     
+    <script src='fullcalendar/main.js'></script>
     <script src="../../core/lib/customize.js"></script>
 
     <script>