While this repo isn't necessarily meant as a direct learning resource, it's still going to be the first thing some people encounter when trying to get hands-on with Halogen.
Having the component in here as App/Button.purs is not very helpful with that, as in normal situations it would be something like App/Component.purs, which then might well have a button inside it, or a child button component or whatever. Basically, I feel like straight out of the box it's set up wrong for what someone would actually want as a starting point for a project.