fix typo in dir name

modules/nixos/performance-tuning/default.nix

@@ -0,0 +1,23 @@
+{ config, lib, pkgs, namespace, ... }:
+
+let
+  cfg = config.${namespace}.performance-tuning;
+in {
+  options.${namespace}.performance-tuning.enable = lib.mkEnableOption "XFCE desktop environment";
+  config = lib.mkIf cfg.xfce.enable {
+    boot.kernelParams = [
+      "nvme_core.default_ps_max_latency_us=0"
+    ];
+
+    boot.kernel.sysctl = {
+      "vm.swappiness" = 10;
+      "vm.dirty_ratio" = 10;
+      "vm.dirty_background_ratio" = 5;
+    };
+
+    services.pipewire.extraConfig.pipewire."context.properties" = {
+      "default.clock.quantum" = 256;
+      "default.clock.min-quantum" = 128;
+    };
+  };
+}