Add organizers and people?

[mblayman]

We could humanize (har har) the community site by starting to include some people who are involved. A simple start would be to add the organizers for each group, but there could be further options that open up in the future if we could reference people on the site.

[mblayman]

Thinking about this more. In the groups app, I think we'd add:

• Person model
• Membership model as the ManyToMany through table that could be added to Group.
• Membership should minimally include a title field. This could be used for job titles like "CEO" or community titles like "Co-organizer".