Basic NixOS Modules

We've all been there. We start playing with our NixOS config and see a cool blog post about modularizing your config. That would be so cool! ... wait how do modules work? The documentation is pretty sparse. And those "beginner" blog posts about modules are so beginner friendly.

So we are going to play with and build our own modules. But we aren't going to build packages; our output is going to be plaintext. We are going to see and feel how each of our options influences the output.