fix link to ui reference

Author: tony-xlh

_includes/sidelist-full-tree.html

@@ -22,7 +22,7 @@
          <li><a href="{{ site.bbs_app }}release-notes/android.html" class="otherLinkColour">Android App</a></li>
      </ul>
 </li>
-<li><a href="{{ site.bbs_app }}ui-reference.html" class="otherLinkColour">UI Reference</a></li>
+<li><a href="{{ site.bbs_app }}ui-reference/" class="otherLinkColour">UI Reference</a></li>
 <li><a href="{{ site.bbs_core }}faq.html" class="otherLinkColour">FAQ</a></li>