Migrated from default.nix to configuration.nix

modules/system/default.nix

@@ -1,4 +1,4 @@
-{ ... }:
+{ outputs, config, lib, ... }:
 
 {
   imports = [
@@ -27,4 +27,39 @@
 
     ./display-managers/default.nix
   ];
+
+  options = {
+    settings.hostname = lib.mkOption {
+      type = lib.types.str;
+      description = ''
+        Set hostname of the system
+      '';
+    };
+  };
+
+  config = {
+  	nixpkgs = {
+  		overlays = [
+  			outputs.overlays.unstable-packages
+  			outputs.overlays.additions
+  			outputs.overlays.modifications
+  		];
+  	};
+
+    nix.settings = {
+      experimental-features = [ "nix-command" "flakes" ];
+
+      substituters = [
+        "https://nix-community.cachix.org"
+        "https://cosmic.cachix.org/"
+      ];
+
+      trusted-public-keys = [
+        "cosmic.cachix.org-1:Dya9IyXD4xdBehWjrkPv6rtxpmMdRel02smYzA85dPE="
+        "nix-community.cachix.org-1:mB9FSh9qf2dCimDSUo8Zy7bkq5CX+/rkCWyvRCYg3Fs="
+      ];
+    };
+
+  	networking.hostName = config.settings.hostname;
+  };
 }