#1554: introduce "done" status for essays

A new status for essays has been added, "done," making the status options:

1. (nothing) = essay has not been edited and is not ready for any rendering
2. staging = essay is already in staging or is ready for pull to staging to check rendering
3. published = essay is already in edition640 or is ready for pull to edition640
4. done = essay is in edition640 and no further pulls from google drive will be completed

This means that no further edits in GD will be reflected in the essays marked "done" and these essays are deemed good enough in their edition640 state to stop continued editing.

Based on editing status by NJR and PHS in both Annotation tracking and metadata GD sheet (tab "render") and workflow in https://github.com/cu-mkp/m-k-annotation-data/projects/1, change status of appropriate essays to "done"

Done