move systems into a separate directory

systems/default.nix

@@ -0,0 +1,44 @@
+{
+  lib,
+  inputs,
+  ...
+}: let
+  # shamelessly borrowed from https://github.com/getchoo/flake/blob/94dc521310b34b80158d1a0ab65d4daa3a44d81e/systems/default.nix
+  toSystem = builder: name: args:
+    (args.builder or builder) (
+      (builtins.removeAttrs args ["builder"])
+      // {
+        modules =
+          args.modules
+          ++ [
+            ./common.nix
+
+            ./${name}
+            ./${name}/hardware-configuration.nix
+
+            {networking.hostName = name;}
+          ];
+        specialArgs = inputs;
+      }
+    );
+
+  mapNixOS = lib.mapAttrs (toSystem inputs.nixpkgs.lib.nixosSystem);
+
+  desktop = with inputs; [
+    ./desktop.nix
+    lanzaboote.nixosModules.lanzaboote
+    home-manager.nixosModules.home-manager
+  ];
+in {
+  flake.nixosConfigurations = mapNixOS {
+    fuji = {
+      system = "x86_64-linux";
+      modules = desktop;
+    };
+
+    kilimandjaro = {
+      system = "x86_64-linux";
+      modules = desktop;
+    };
+  };
+}