refactor: forget docker_repo.var

[wesleyboar]

Overview

Forget docker_repo.var. A CMS built from this template would be alone in its repo, so explicitly name example Docker Hub repo.

Related

• mimics refactor: delete unnecessary env files Core-CMS#966
• similar to refactor: forget docker_repo.var APCD-CMS#18
• similar to refactor: forget docker_repo.var Texascale-CMS#20

Changes

• deletes docker_repo.var reference and requirement
• documents another custom-cms value to change
• deletes .var steps in make setup

Testing

Run make setup and see it does not mention .var files but continues to:

Building and starting Docker containers...

The only other affected commands are make build-full, make publish, make publish-latest, but we wouldn't run those and a repo created form this template would use GitHub Actions.