Link to usage data (ref syncthing/website#17)

gui/assets/lang/lang-en.json

@@ -196,6 +196,7 @@
    "Upgrading": "Upgrading",
    "Upload Rate": "Upload Rate",
    "Uptime": "Uptime",
+   "Usage": "Usage",
    "Use HTTPS for GUI": "Use HTTPS for GUI",
    "Version": "Version",
    "Versions Path": "Versions Path",

gui/index.html

@@ -465,9 +465,12 @@
         <li><a class="navbar-link" href="http://syncthing.net/" target="_blank"><span class="glyphicon glyphicon-home"></span>&nbsp;<span translate>Home page</span></a></li>
         <li><a class="navbar-link" href="http://docs.syncthing.net/" target="_blank"><span class="glyphicon glyphicon-book"></span>&nbsp;<span translate>Documentation</span></a></li>
         <li><a class="navbar-link" href="https://forum.syncthing.net" target="_blank"><span class="glyphicon glyphicon-question-sign"></span>&nbsp;<span translate>Support</span></a></li>
+        <li><a class="navbar-link" href="https://data.syncthing.net/" target="_blank"><span class="glyphicon glyphicon-stats"></span>&nbsp;<span translate>Usage</span></a></li>
+
         <li><a class="navbar-link" href="https://github.com/syncthing/syncthing/releases" target="_blank"><span class="glyphicon glyphicon-info-sign"></span>&nbsp;<span translate>Changelog</span></a></li>
         <li><a class="navbar-link" href="https://github.com/syncthing/syncthing/issues" target="_blank"><span class="glyphicon glyphicon-warning-sign"></span>&nbsp;<span translate>Bugs</span></a></li>
         <li><a class="navbar-link" href="https://github.com/syncthing/syncthing" target="_blank"><span class="glyphicon glyphicon-wrench"></span>&nbsp;<span translate>Source Code</span></a></li>
+
         <li><a class="navbar-link" href="https://twitter.com/syncthing" target="_blank"><span class="glyphicon glyphicon-send"></span>&nbsp;Twitter</a></li>
       </ul>
     </div>