Create a sample app or clear instructions about pg_party

[rkrage]

Hi @igorkasyanchuk,

Yes, better documentation is in progress. There is (sort of) a sample app that's used in the integration tests.

Here's an example of how you'd use the migrations: https://github.com/rkrage/pg_party/blob/8f326b511e1f6a035a88d86d27af3aa07423de6e/spec/internal/db/schema.rb

And the integration tests that exercise these tables: https://github.com/rkrage/pg_party/tree/8f326b511e1f6a035a88d86d27af3aa07423de6e/spec/integration/model

[rkrage]

Will likely be tackled in #33