Feature: Docker image

For my projects I'm usually building a Docker image with the migration scripts included. Now I'm building images from scratch in various projects, but in order to safe some CI minutes I'm looking to build a single "tern" base image for all of my projects.

If you are interested in a Docker image for this repository, I can commit a Dockerfile here and (help) setup a CI environment. This can be either Github actions, or directly building it on Docker hub.

Start by reviewing the repository's current build and migration entry points, then determine what the proposed Dockerfile must include. Compare GitHub Actions and Docker Hub as the build location; done means a documented, repeatable tern base image containing the migration scripts and a defined image-publishing path.

Written by the indexing model from the issue text.