Mostly managed by Nix and heavily inspired by https://github.com/nmasur/dotfiles.
The library functions buildHome, buildNixos, and buildDarwin will crawl through the hosts directory to find any default.nix files and use those as input modules. For example, hosts/x86_64-linux/window/default.nix will create a flake named window, and use the configurations defined there. If you want to use that one, then you can do nixos-rebuild switch --flake .#window. nixos-rebuild switch will also save the flake name you used to $NIXOS_FLAKE_NAME.
modules defines the options for setting up applications. Generally, modules/home-manager is for user level stuff, and modules/nixos and modules/darwin are for system level stuff.
static has static assets. Most notably, it contains my Neovim config, which is simply symlinked into ~/.config. I don't know, I don't feel like rewriting it into Nix.
tools has random one-off scripts, including a bootstrap installer (which as of 12/01/2025 I still haven't tested).
If for whatever reason someone else decides to copy this, just update the values in config.json and you should be fine. Remember to add your own hardware-configuration.nix files to the hosts.