feat(waybar): Add individual module

nixos/modules/desktop/waybar/default.nix

@@ -0,0 +1,18 @@
+{ config, lib, pkgs, ... }:
+
+let
+  cfg = config.sisyphus.desktop.waybar;
+in {
+  options.sisyphus.desktop.waybar.enable = lib.mkEnableOption "Waybar";
+
+  config = lib.mkIf cfg.enable {
+    environment.systemPackages = with pkgs; [
+      libnotify
+      playerctl
+      jq
+      j4-dmenu-desktop
+    ];
+
+    programs.waybar.enable = true;
+  };
+}