docs: Add link to action bar design pattern.

</ul>

<p>Use CABs whenever you allow the user to select data via long press. You can control the action

content of a CAB in order to insert the actions you would like the user to be able to perform.</p>

<p>For more information, refer to the "Selection" pattern.</p>

<p>For more information, refer to the <a href="{@docRoot}design/patterns/selection.html">Selection

pattern</a>.</p>

<h2 id="elements">Action Bar Elements</h2>

<h4>Tabs</h4>