Update README
Update README

The note about creating the database through Compose was not only wrong,
it wasn't needed. The Postgres image handles this step for us.

PyGotham/pygotham,pathunstrom/pygotham,djds23/pygotham-1,djds23/pygotham-1,PyGotham/pygotham,PyGotham/pygotham,djds23/pygotham-1,djds23/pygotham-1,pathunstrom/pygotham,pathunstrom/pygotham,pathunstrom/pygotham,PyGotham/pygotham,djds23/pygotham-1,PyGotham/pygotham,pathunstrom/pygotham