Added link to 3.2.1 docs in the footer, just like Bootstrap

Closes #2200

src/_includes/footer.html

@@ -16,6 +16,7 @@
       Thanks to <a href="http://maxcdn.com"><i class="fa fa-maxcdn"></i> MaxCDN</a> for providing the excellent <a href="http://www.bootstrapcdn.com/#fontawesome_tab">BootstrapCDN for Font Awesome</a>
     </div>
     <div class="project">
+      <a href="{{ page.relative_path }}3.2.1">Font Awesome 3.2.1 docs</a> &middot;
       <a href="{{ site.fontawesome.github.url }}">GitHub Project</a> &middot;
       <a href="{{ site.fontawesome.github.url }}/issues">Issues</a>
     </div>