puppetboard/templates/layout: Restoring the footer but referencing Puppet Community

@daenney would rather have the footer reference the Puppet Community organization
than completing removing this bar.

Also adding a reference in README.rst about the available Google Group

puppetboard/templates/layout.html

@@ -54,6 +54,12 @@
       <i class="large arrow up icon"></i>
     </div>
 
+    <footer class="ui absolute fixed bottom">
+      <div>
+        Copyright &copy; 2013-{{ now('%Y') }} <a href="https://github.com/puppet-community" target="_blank">Puppet Community</a>. <span style="float:right">Live from PuppetDB.</span>
+      </div>
+    </footer>
+
     {% if config.OFFLINE_MODE %}
     <script src="{{ url_for('static', filename='js/jquery.min.js') }}"></script>
     <script src="{{ url_for('static', filename='js/semantic.min.js') }}"></script>