Arm support

[pbarker]

Any chance we could add arm support? Happy to help contribute

[thehale]

I don't yet have experience adding ARM support on Docker, but happy to review a PR!

Here's what I would expect from a PR:

• Dockerfile improvements to support multi-arch builds
• Updated make commands for building the image for each architecture (so users can run local builds for any individual architecture)
• Updated GitHub Actions scripts to build/publish the multi-arch builds to DockerHub.

Implementation Guide
Here are the articles I'd saved from previous cursory research into multi-arch/multi-platform builds:

• https://docs.docker.com/build/building/multi-platform/
• https://www.docker.com/blog/multi-arch-build-and-images-the-simple-way/

Hopefully those articles are a useful starting point!