Add Docker Support

[magneticstain]

Feature Summary

Along with being able to run Plexer locally, we should also support the ability to run Plexer using Docker.

Benefit

Docker is a popular technology that makes managing and running individual tools like this easier.

Additional context

We should support hosting the Docker image on both Docker Hub and Github.

https://docs.docker.com/docker-hub/
https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry

Child Issues

• #43
• #44
• #45