feat: add container image ci build to github package

[RicoToothless]

It would be nice to publish container images to GitHub Package for the public community.

The image tag is steps.tag.outputs.tag from the previous "Get tag value" step.

Ref: https://docs.github.com/en/actions/publishing-packages/publishing-docker-images

[vgorkavenko]

@infloop is this acceptable or can we make dockerhub for this app public?