Studio: adding in doc URL logic for course re-run help link

cms/templates/course-create-rerun.html

 <%inherit file="base.html" />
-
+<%def name="online_help_token()"><% return "course_rerun" %></%def>
 <%! from django.utils.translation import ugettext as _ %>
 <%! from django.core.urlresolvers import reverse %>
 
@@ -146,8 +146,8 @@ require(["domReady!", "jquery", "jquery.form", "js/views/course_rerun"], functio
           </div>
 
           <div class="bit external-help">
-            <a href="" class="button external-help-button">${_("Learn more about Course Re-runs")}</a>
-          <div class="bit">
+            <a href="${get_online_help_info(online_help_token())['doc_url']}" target="_blank" class="button external-help-button">${_("Learn more about Course Re-runs")}</a>
+          </div>
         </aside>
 
       </section>