tree-wide change. seperated config from 'real' modles.

configs/nixos/common.nix

@@ -0,0 +1,39 @@
+{
+  config,
+  pkgs,
+  inputs,
+  outputs,
+  ...
+}: {
+  nix = {
+    package = pkgs.nixFlakes;
+    extraOptions = ''
+      experimental-features = nix-command flakes
+    '';
+    optimise.automatic = true;
+    settings = {
+      auto-optimise-store = true;
+    };
+    gc = {
+      automatic = true;
+      dates = "weekly";
+      options = "--delete-older-than 30d";
+    };
+  };
+
+  # Allow unfree packages
+  nixpkgs.config.allowUnfree = true;
+
+  # packages that should be on every system.
+  environment.systemPackages = with pkgs; [
+    neovim # Do not forget to add an editor to edit configuration.nix! The Nano editor is also installed by default.
+  ];
+
+  imports = [
+    ../../modules/hostopts.nix
+  ];
+
+  home-manager.useGlobalPkgs = true;
+  home-manager.useUserPackages = true;
+  home-manager.extraSpecialArgs = {inherit inputs outputs;};
+}