feat(v2): Add a note about jquery-ui

Author: Urigo

demo/index.html

@@ -178,6 +178,7 @@ <h4>This calendar uses the extended form</h4>
                 </div>
             </div>
             <h3>How?</h3>
+            <div>* The jQuery UI files are only necessary if you plan to do drag & drop / resizing</div>
                 <pre class="prettyprint linenums">
 &lt;div ui-calendar="uiConfig.calendar" class="span8 calendar" ng-model="eventSources"&gt;&lt;/div&gt;