Add minimal modular setup

modules/nixos/system/default.nix

@@ -0,0 +1,7 @@
+{ pkgs, lib, ... }: {
+  imports = [
+    ./locale.nix
+    ./programs.nix
+    ./services.nix
+  ];
+}

modules/nixos/system/locale.nix

@@ -0,0 +1,10 @@
+{ pkgs, lib, config, ... }: {
+  time.timeZone = "Etc/UTC";
+
+  i18n.defaultLocale = "en_US.UTF-8";
+  console = if config.mods.xorg.enable then {
+    useXkbConfig = true;
+  } else {
+    keymap = "us";
+  };
+}

modules/nixos/system/programs.nix

@@ -0,0 +1,11 @@
+{ pkgs, lib, ... }: {
+  environment.systemPackages = with pkgs; [
+    vim
+    wget
+  ];
+
+  programs.gnupg.agent = {
+    enable = true;
+    enableSSHSupport = true;
+  };
+}

modules/nixos/system/services.nix

@@ -0,0 +1,3 @@
+{ pkgs, lib, ... }: {
+  services.openssh.enable = true;
+}