refactor: make the whole thing more generic

modules/nixos/hardware/cc1.nix

@@ -0,0 +1,29 @@
+{ pkgs, lib, config, username, ... }:
+with lib;
+
+let cfg = config.hardware.cc1;
+
+in {
+  options.hardware.cc1 = {
+    enable = mkEnableOption "Enable CC1 optimizations";
+    layout = mkOption {
+      type = with lib.types; enum [ "cc1-thea" ];
+      default = "cc1-thea";
+    };
+  };
+
+  config = mkIf cfg.enable {
+    # TODO: per-device layout?
+    console.useXkbConfig = true;
+    services.xserver.xkb = {
+      layout = cfg.layout;
+      extraLayouts.cc1-thea = {
+        description = "A CC1 optimized layout";
+        languages = [ "eng" "ger" ];
+        symbolsFile = ./${cfg.layout};
+      };
+    };
+
+    users.users.${username}.extraGroups = [ "dialout" ];
+  };
+}