refactor: Remove 'defaults' abstraction

modules/nixos/documentation.nix

@@ -0,0 +1,24 @@
+{ config, lib, pkgs, ... }:
+
+let cfg = config.sydnix.documentation;
+in {
+  options.sydnix.documentation = {
+    enable = lib.mkEnableOption "man and info pages" // {
+      default = true;
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    documentation = {
+      man.enable = true;
+      info.enable = true;
+    };
+
+    environment.systemPackages = with pkgs; [
+      man-pages
+      stdman
+      man-pages-posix
+      stdmanpages
+    ];
+  };
+}