Publish AFJ mediator image to github container registry

[TimoGlastra]

It would be nice to be able to quickly start an AFJ mediator using a docker container.

TODO:

• Rename this repo to aries-docker (or another name that is more descriptive, it's not just indy-nodejs)
• Create Dockerfile that sets everything up for AFJ and the mediator
  • can be taken from the indy docker file in this repo
  • or from the AFJ dockerfile
• Write a github action that automatically publishes the indy-nodejs and afj mediator images to the new github container registry
  • ideally with a dispatch so we can manually release
  • include the afj version into the docker iamge name
  • include the nodejs version into the docker image name
  • https://docs.github.com/en/packages/working-with-a-github-packages-registry/working-with-the-container-registry
• Add documentation on how to run the mediator yourself using the published docker image
• ... other things?

Current mediator setup (https://mediator.animo.id): https://github.com/animo/cloud-setup/blob/main/docker-compose-mediator.yml

Related to this issue: openwallet-foundation/credo-ts#240

If it works well we can eventually move it to the hyperledger org.