add RSS Link to the footer

Signed-off-by: xFuture603 <daniel.xfuture@googlemail.com>

Author: xFuture603

themes/devsec/layouts/partials/footer.html

@@ -5,4 +5,5 @@
   <li><a href="https://galaxy.ansible.com/devsec/hardening">Ansible Galaxy</a></li>
   <li><a href="https://supermarket.getchef.com/cookbooks?q=hardening">Chef Community</a></li>
   <li><a href="https://forge.puppetlabs.com/hardening">Puppet Forge</a></li>
+  <li><a href="/blog/index.xml">RSS</a></li>
 </ul>