Update CITI Training instructions (#2181)

This adds some new screenshots and clarifying instructions to the
/about/citi-course/ page.

physionet-django/templates/about/citi_course.html

@@ -20,6 +20,10 @@ <h1>CITI Course Instructions</h1>
     <img src="{% static 'images/about/citi-course-instructions-4.png' %}" alt="Citi Course instructions 4" class="screenshot">
     <li>Once submitted, you should see the 'Data or Specimens Only Research' and 'Conflicts of Interest' modules. Please complete these modules.</li>
     <img src="{% static 'images/about/citi-course-instructions-5.png' %}" alt="Citi Course instructions 5" class="screenshot">
+    <li>Please make sure when submitting your CITI training application, that you upload the training report rather than the certificate. You can find your training report under 'Records' at the top of the webpage. From there, you can download your training report by selecting 'View-Print-Share' under Completion Record.</li>
+    <img src="{% static 'images/about/citi-course-instructions-6.png' %}" alt="Citi Course instructions 6" class="screenshot">
+    <li>Click 'view/print' under Completion Record to get the full training report to upload on PhysioNet.</li>
+    <img src="{% static 'images/about/citi-course-instructions-7.png' %}" alt="Citi Course instructions 7" class="screenshot">
   </ol>
 </div>
 {% endblock %}