Collaborative editing of transcript file

Hi there. I'm teaching a large class on zoom and thought it would be good if students took turns tidying up a transcript  of one class each, which would mean all transcripts get edited, and these student-edited transcripts displayed as the official transcripts next to the videos when people watched them. 

However, there seems to be no way to do this, since the only way I know to edit the officially displayed transcript is to log on as host. I have access to the .vtt files and could send them to students for editing, but I don't see any way to re-upload the .vtt files to display next to the video once edited in that format.

Am I missing something or is this not possible?