Transcript synchronization wiki page updated

I've updated the wiki page to include issues identified at today's meeting. Further improvements are welcome (ideally by editing the wiki page, but comments on the mailing list are also appreciated).
https://www.w3.org/WAI/APA/task-forces/research-questions/wiki/Transcript_synchronization#Issues_Identified_by_the_Task_force
I hope these changes suffice for the APA Working Group's forthcoming communications concerning TPAC meeting planning. We expect to resume discussion at next week's Task Force meeting.