added non-tested Dockerfile & updated video gauges

rowers/templates/embedded_video.html

@@ -411,6 +411,17 @@ function copyText() {
       </p>
       {% endif %}
     </li>
+    <li class="grid_2">
+      <p>We're building Gauges to show the video data based on the
+        <a href="https://developers.google.com/chart">Google charts API</a>.
+        You can contribute by developing your own gauge in
+        <a href="https://jsfiddle.net/">JSFiddle</a> like
+        <a href="https://jsfiddle.net/roosendaalsander/5xrez3bu/">this example</a>.
+        Please send us the link to the JSFiddle example by email using the
+        <a href="/rowers/email/">Contact Form</a> and we'll discuss the possibilities
+        with you.
+      </p>
+    </li>
   </ul>
 </form>
 <p>&nbsp;</p>