Publish docker images to a repository

Similar to #51

It would make it easier for people to have a published image, either on GitHub's ghcr.io or Docker Hub.
Popular repositories like [Authentik](https://github.com/orgs/goauthentik/packages?repo_name=authentik) and [Immich](https://github.com/orgs/immich-app/packages?repo_name=immich) do it like this.

Using images makes patch/vulnerability management easier for end users so they don't have to have a specific workflow per app.
Instead they would just "docker compose pull" or "docker pull" to get the latest version.

Kind regards,

Lesley

Start by reviewing the related issue #51 and the repository's current Docker image and release setup. Define whether GitHub Container Registry or Docker Hub is the target, then verify that users can retrieve the published image with docker pull or docker compose pull.

Written by the indexing model from the issue text.