Start tucking logic away behind the scenes

[rustprooflabs]

This PR starts moving faker logic into stored procedures, and introduces a custom pgosm-flex-faker Docker image.

Move store creation logic into stored procedure. Add Dockerfile and update steps for adjusted usage.

Docker image on Docker Hub.

docker pull rustprooflabs/pgosm-flex-faker

[rustprooflabs]

Md Book should be published at https://faker.pgosm-flex.com/ before too long...

[rustprooflabs]

Docs say it can be an hour before it's properly available via TLS, that seems to be the only part of that not quite hooked up right.

"It can take up to an hour for your site to become available over HTTPS after you configure your custom domain. After you update existing DNS settings, you may need to remove and re-add your custom domain to your site's repository to trigger the process of enabling HTTPS. "