Visual enhancement for custom JS tree widget

* adds proper css behaviour for collapsed icon
* adds minor js comments

konova/static/css/konova.css

@@ -262,4 +262,13 @@ Similar to bootstraps 'shadow-lg'
     padding-left: 2em;
 }
 
- */
+ */
+.collapse-icn > i{
+    transition: all 0.3s ease;
+}
+.collapsed .collapse-icn > i{
+    transform: rotate(-90deg);
+}
+.tree-label.badge{
+    font-size: 90%;
+}