Add examples of html5 videos to docstrings.

common/lib/xmodule/xmodule/video_module/video_module.py

@@ -9,6 +9,11 @@ It's new improved video module, which support additional feature:
 in-browser HTML5 video method (when in HTML5 mode).
 - Navigational subtitles can be disabled altogether via an attribute
 in XML.
+
+Examples of html5 videos for manual testing:
+    https://s3.amazonaws.com/edx-course-videos/edx-intro/edX-FA12-cware-1_100.mp4
+    https://s3.amazonaws.com/edx-course-videos/edx-intro/edX-FA12-cware-1_100.webm
+    https://s3.amazonaws.com/edx-course-videos/edx-intro/edX-FA12-cware-1_100.ogv
 """
 import json
 import logging