Add chat tab to /info page of courseware.

lms/templates/courseware/info.html

@@ -113,6 +113,13 @@ from openedx.core.djangolib.markup import HTML, Text
   </div>
 </main>
 
+<script>
+  var full_url = window.location.href;
+  full_url = full_url.substring(0, full_url.length-4) + 'chat';
+  tab_list = document.querySelector('.course-tabs');
+  tab_list.innerHTML = tab_list.innerHTML + '<li class="tab"><a href="' + full_url + '">Chat</a></li>';
+</script>
+
 <%static:require_module_async module_name="js/dateutil_factory" class_name="DateUtilFactory">
     DateUtilFactory.transform(iterationKey=".localized-datetime");
 </%static:require_module_async>