setup docs and client-side geocoding

I suggested to you guys that server-side geocoding would be simpler to implement, but I looked this morning and saw that Google limits the number of queries per IP to 2500/day:

https://developers.google.com/maps/articles/geocodestrat#server

So this PR changes it to work on the client side. It also limits results to the Twin Cities metro, so it fixes a bug where "Minneapolis, MN" can be added to the search query multiple times.

In setting up the project, I noticed there wasn't a DB migration or any automated way to import data, so I added that as well.

Thanks for this awesome project!