Is there a tutorial for making automated Silverblue derivatives ISOs via GitHub for 5th graders?

All of the examples on how to automatically build ISOs using GitHub workflows only provide instructions to pull the images from the GitHub registry. The READMEs do not provide a step-by-step on how to build the image from the Containerfile, or how to generate the ISO.

Could anybody be so kind to provide couple of links with the ABC of this process?