Right when event posts, we should help event get its first 5-7 RSVPs

[vs77bb]

This is most obviously through an 'invite' feature, where it gets invites from people who have come

• past events you've hosted
• what else?

[vs77bb]

Here's me helping with Archaeology and/of The Web, a really cool event that has 0 RSVPs so far for Friday.

Not only a Convo issue to solve, but getting at least one great listener (if not 2-3) should be a design goal of the app towards great dialogue.

[vs77bb]

Depends on #355 in some ways... some type of "profile" being in place.