Tried using this repo in  GitHub Codespaces and even locally at the docker-compose command is not correct and does not create the container.

I split up the commands to just do docker-compose build and then docker-compose up -d and that worked.

I suspect the syntax on docker-compose --progress plain build is wrong.

One more question: How did you configure the Pages section of the repo? I'm getting a 404 error when i try to access the page.

This works fine as long as the everything is in the same repo, but ideally you would want to have a separate repo for the documentation. There will be other documentation besides the class files and we want to keep them on a distinct cadence from code updates. 

When I try to use the INPUT reference to another repo, it fails with source is not a readable file or directory... skipping. I've read through the documentation and I can't find anything related to referencing a remote repo.

I'll post to their listserv and see if this is possible.