feat: add docker github action

[M0NsTeRRR]

Description

Add a GitHub Action to publish a Docker image to ghcr.io when a new release is tagged. I don't know if you want to use this image in the compose file or add a message on the documentation for production usage. Let me know :)

Motivation and Context

I would like to deploy Hyperglass in a Kubernetes environment and avoid building the image manually.

Tests

Tested in my fork. You can pull my image from there.