Event organizer coordination mechanism

Initially brought up here: https://github.com/codeforboston/ecosystem-cal/issues/11#issuecomment-39027338
Via Chris Osgood:

> Great issue to raise.
> I wonder, if in addition to the calendar, you create a google group that civic tech event organizers use (1) to check dates before they are put on the calendar or (2) to make event organizers know when something is going on the calendar.

The solution could be a mailing list, or something else. I'd like to hold off on setting something like this up until we've at least launched our MVP calendar and can establish a feedback loop with the ecosystem.

Start by reviewing the linked discussion in issue #11 and the current MVP calendar status. Define whether organizer coordination should use a mailing list, Google Group, or another mechanism, and treat the work as done when a specific approach is selected after the MVP launch and feedback loop.

Written by the indexing model from the issue text.