Create docker-publish.yml

[rtm516]

Closes #226

[rtm516]

This may want to be updated to use the new container registry or use an alternative service mentioned in the linked issue.
https://docs.github.com/en/packages/guides/migrating-to-github-container-registry-for-docker-images

[rtm516]

Note: To use containers built by this you need to login to the github package registry which isn't super easy or accessible for users.