Move behavior description from HTML comment to JSDoc. Fixes #117

Author: s-kulikov

paper-item-behavior.html

@@ -12,14 +12,14 @@
 <link rel="import" href="../iron-behaviors/iron-button-state.html">
 <link rel="import" href="../iron-behaviors/iron-control-state.html">
 
-<!--
-`PaperItemBehavior` is a convenience behavior shared by <paper-item> and
-<paper-icon-item> that manages the shared control states and attributes of
-the items.
--->
-
 <script>
-  /** @polymerBehavior Polymer.PaperItemBehavior */
+  /**
+   * `PaperItemBehavior` is a convenience behavior shared by <paper-item> and
+   * <paper-icon-item> that manages the shared control states and attributes
+   * of the items.
+   *
+   * @polymerBehavior Polymer.PaperItemBehavior
+   */
   Polymer.PaperItemBehaviorImpl = {
     hostAttributes: {
       role: 'option',