Major config overhaul: use custom modules, setup for multi-host config, and less boilerplate

modules/user/art/default.nix

@@ -0,0 +1,22 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.userSettings.art;
+in {
+  options = {
+    userSettings.art = {
+      enable = lib.mkEnableOption "Enable art apps";
+    };
+  };
+
+  config = lib.mkIf cfg.enable {
+    home.packages = with pkgs; [
+      gimp
+      krita
+      pinta
+      inkscape
+      libresprite
+    ];
+    userSettings.blender.enable = true;
+  };
+}