Perhaps because there isn't really a starting point for this? Different people use nix for different things, perhaps a bit differently (e.g. whether they use f

Perhaps because there isn't really a starting point for this? Different people use nix for different things, perhaps a bit differently (e.g. whether they use flakes, home-manager, what channels do they follow). Each language has their own way of building packages, and different 'framework' in nix to build for them (usually about how to pull the dependencies in a reproducible way). And there are things that readers are expected to know such as basic shell scripts, paths, etc.