[DOC] add link Biostar queries.

docs/templates/sidebar-intro.html

@@ -7,7 +7,9 @@
   <li><a target="_blank" href="https://github.com/arq5x/bedtools">Source @ GitHub</a></li>
   <li><a target="_blank" href="https://bedtools.googlecode.com">Releases @ Google Code</a></li>
   <li><a target="_blank" href="http://groups.google.com/group/bedtools-discuss">Mailing list @ Google Groups</a></li>
+  <li><a target="_blank" href="http://www.biostars.org/show/tag/bedtools/">Queries @ Biostar</a></li>
   <li><a target="_blank" href="http://quinlanlab.org">Quinlan lab @ UVa</a></li>
+
 </ul>
 
 <h3>Sources</h3>