Adding gitter channel to the dashboard

Author: datapythonista

pandas/dashboard.html

@@ -32,6 +32,7 @@
             <h1 style="margin-left: 30px;">#pandasSprint</h1>
             <ol style="margin-left: 30px;">
                 <li><input type="checkbox"><a href="https://python-sprints.github.io/pandas/guide/pandas_setup.html">Install the environment</a></li>
+                <li><input type="checkbox">Join the <a href="https://gitter.im/py-sprints/pandas-doc">Gitter channel</a></li>
                 <li><input type="checkbox">Your local organizers will assign you a documentation page</li>
                 <li><input type="checkbox">
                     Understand <b>well</b> what the functionality you're documenting does