Added target='_blank' to both href attributes

lms/templates/instructor/instructor_dashboard_2/cohort-group-header.underscore

@@ -12,10 +12,10 @@
     <div class="setup-value">
         <% if (cohort.get('assignment_type') == "manual") { %>
             <%- gettext("Learners are added to this cohort only when you provide their email addresses or usernames on this page.") %>
-            <a href="http://edx.readthedocs.org/projects/edx-partner-course-staff/en/latest/course_features/cohorts/cohort_config.html#assign-learners-to-cohorts-manually" class="incontext-help action-secondary action-help"><%= gettext("What does this mean?") %></a>
+            <a href="http://edx.readthedocs.org/projects/edx-partner-course-staff/en/latest/course_features/cohorts/cohort_config.html#assign-learners-to-cohorts-manually" class="incontext-help action-secondary action-help" target="_blank"><%= gettext("What does this mean?") %></a>
         <% } else { %>
             <%- gettext("Learners are added to this cohort automatically.") %>
-            <a href="http://edx.readthedocs.org/projects/edx-partner-course-staff/en/latest/course_features/cohorts/cohorts_overview.html#all-automated-assignment" class="incontext-help action-secondary action-help"><%- gettext("What does this mean?") %></a>
+            <a href="http://edx.readthedocs.org/projects/edx-partner-course-staff/en/latest/course_features/cohorts/cohorts_overview.html#all-automated-assignment" class="incontext-help action-secondary action-help" target="_blank"><%- gettext("What does this mean?") %></a>
         <% } %>
     </div>
 </div>