feat: Add package option and installation, improve styling

nethack.nix

@@ -1,8 +1,4 @@
-{
-  config,
-  lib,
-  ...
-}:
+{ config, lib, pkgs, ... }:
 
 with lib;
 with types;
@@ -56,6 +52,12 @@ in
   options.programs.nethack = {
     enable = mkEnableOption "nethack configuration";
 
+    package = mkOption {
+      type = types.package;
+      default = pkgs.nethack;
+      description = "Nethack package to install";
+    };
+
     nethack_options = mkOption {
       type = attrsOf (oneOf [bool int str]);
       default = {};
@@ -199,10 +201,20 @@ in
   };
   # }}}
 
-  config = {
-    home.file.".nethackrc" = with config.programs.nethack; {
-      inherit enable;
-      text = generateNethackrc config.programs.nethack;
+  config = let
+    cfg = config.programs.nethack;
+  in {
+    home = {
+      packages = mkIf cfg.enable [
+        cfg.package
+      ];
+
+      file = {
+        ".nethackrc" = {
+          inherit (cfg) enable;
+          text = generateNethackrc cfg;
+        };
+      };
     };
   };
 }