Include workflow and Dockerfile changes only

[afbase]

Summary

this is the branch for just the docker package building.

Related Issues

related to #108 and #110

Changes

• Feature implementation

Checklist

• I have tested the changes (including writing unit tests).
• I confirm that my implementation aligns with the canonical Typescript implementation and/or atproto spec
• I have updated relevant documentation.
• I have formatted my code correctly
• I have provided examples for how this code works or will be used

[afbase]

@rudyfraser

I'm still getting 403s to make an image on blacksky-algorithms organization. Tomorrow, I'm going to see if i can make images on my own account to unblock me for now.

Would you mind trying to re-run this job? I'm wondering if the github.actor matters?

[afbase]

Workflow does the follow:

1. determine which workspace members need to be built and tested.
2. determine which dockerfiles need to be build, if any. docker will run a build only when a fork repository makes a PR. When blacksky-algorithms runs (e.g. upon merge), docker will run a build-and-push to create a package.