Documentation updates to add missing fields and verify descriptions of existing…

Documentation updates to add missing fields and verify descriptions of existing fields for discussion data

docs/en_us/data/source/internal_data_formats/change_log.rst

@@ -10,6 +10,8 @@ Change Log
 
    * - Date
      - Change
+   * - 21 Feb 14
+     - Added descriptions of new fields to the :ref:`Discussion Forums Data` chapter.
    * - 14 Feb 14
      - Added the ``seek_video`` and ``speed_change_video`` event types to the :ref:`Tracking Logs` chapter.