Add in some better encouragement to write feedback

lms/templates/instructor/staff_grading.html

@@ -75,6 +75,7 @@
   </p>
   <p class="grade-selection-container">
   </p>
+  <h3>Written Feedback</h3>
   <textarea name="feedback" placeholder="Feedback for student (optional)"
             class="feedback-area" cols="70" ></textarea>
 </div>

lms/templates/peer_grading/peer_grading_problem.html

@@ -70,7 +70,9 @@
           <p class="rubric-selection-container"></p>
           <p class="score-selection-container">
           </p>
-          <textarea name="feedback" placeholder="Feedback for student (optional)"
+          <h3>Written Feedback</h3>
+          <p>Please include some written feedback as well.</p>
+          <textarea name="feedback" placeholder="Feedback for student"
                     class="feedback-area" cols="70" ></textarea>
         </div>