Initialise collapsible block so it actually unfolds/folds

static/js/init.js

@@ -3,5 +3,10 @@
 
     $('.sidenav').sidenav();
 
+    /* Initialise collapsible tags block */
+    $(document).ready(function() {
+        $('.collapsible').collapsible();
+    });
+
   }); // end of document ready
 })(jQuery); // end of jQuery name space