Migrate project to issue-based iteration meetings

Currently the Subplot project has an iteration meeting every two weeks, this meeting is held via a video call and the agenda is constructed privately between the members of the call.

If there is to be a wider community of participation in Subplot iterations, we may need to migrate to an issue-based workflow for these iteration meetings.

This issue is to keep the point in our minds, and act as a concentration point for feedback from others about whether or not this is worthwhile yet.