Add id to feedbak element.

Author: shawnbuso

codelab-elements/google-codelab/google_codelab.soy

@@ -85,7 +85,7 @@
     </ol>
   </div>
   {if $feedback}
-  <div class="metadata">
+  <div id="feedback" class="metadata">
     <a target="_blank" href="{$feedback}">
       <i class="material-icons">bug_report</i> Report a mistake
     </a>