DOC: Add docstring

src/core/js/webcaosdb.js

@@ -306,6 +306,14 @@ this.navbar = new function () {
         }
     }
 
+    /**
+     * Hide the given element for certain roles
+     *
+     * @param {string|object} name - The HTML element either as the result
+     *     of a jquery or identified by a jquery selector
+     * @param {array} roles - list of roles for which the given element is
+     *     hidden.
+     */
     this.hideElementForRoles = function (name, roles) {
         var elt = name;
         if (typeof (name) === "string") {