Add automated build and distribution of Docker images

[StephenOman]

🚀 Feature

This feature proposes to add automation (via GitHub Actions) to both the Docker image build process (i.e. image generation) and distribution (via either GitHub Container Registry or Docker Hub).

Motivation

Docker images make it simple to distribute run-time application configurations. For NLE, this means distributing the complete application with compiled NetHack libraries, Python dependencies etc., rather than relying on the user to compile/build them. It also avoids unforeseen problems with different architectures and operating systems by offering a standard application.

Pitch

• Add GitHub action workflow to build the multi-architecture Docker image.
• Add workflow to publish the image to Docker Hub or GitHub Container Registry.
• Update README documentation for users with instructions on retrieving images.

Alternatives

Two options are available, GitHub Container Registry or Docker Hub. Further investigation is required into which one to use.

Additional context

See previous discussion on this topic in PR#16