How do I use the examples? #462

Hi!

Thanks for the project, I've been using it for over a year (what is now the devos example) and it's been of great help!

However, I'm now moving from NixOS to MacOS and I want to refactor my config to accommodate for it.

I fear the devos example may be too much, and cause more problems than it's worth if I try to maintain everything in it, so I was leaning more towards the groupByConfig example, where there's a better separation of OS configs. But I have no idea how to run it 😓

With devos on NixOS it's pretty obvious to me, I just use sudo nixos-rebuild switch, but how am I supposed to use the groupByConfig example in MacOS?

Any help is appreciated, thanks!