Instead of requiring the user to run `yarn install` followed by `yarn
start`, we simply have them run `docker compose up` to start both the
app and Postgres together. This is much easier and reduces the need for
them to install anything else besides Docker. It also makes cleaning up
the example easier.
Provide a working end-to-end example of syncing data from hubs to a
Postgres database.
This should work with no additional dependencies besides what you
install with `yarn install` and Docker.
