Layout
.
├── config # Config files not written in Nix
├── default.nix # Defines module, system-level config,
├── disk-config.nix # Disks, partitions, and filesystems
├── files.nix # Non-Nix, static configuration files (now immutable!)
├── home-manager.nix # Defines user programs
├── packages.nix # List of packages to install for NixOS
├── secrets.nix # Age-encrypted secrets with agenix