[JSDoc] Add annotations

Bulk-add JSDoc annotations, WTD-1482.

platform/forms/src/MCTControl.js

@@ -33,6 +33,8 @@ define(
          * `controls`; this allows plug-ins to introduce new form
          * control types while still making use of the form
          * generator to ensure an overall consistent form style.
+         * @constructor
+         * @memberof platform/forms
          */
         function MCTControl(controls) {
             var controlMap = {};
@@ -103,4 +105,4 @@ define(
 
         return MCTControl;
     }
-);
+);