fix(user): Change fuzzel to walker

modules/user/walker.nix

@@ -0,0 +1,14 @@
+{
+  services = {
+    walker = {
+      enable = true;
+      systemd.enable = true;
+    };
+
+    elephant.enable = true;
+  };
+
+  wayland.windowManager.hyprland.settings.bind = [
+    "$mainMod, D, exec, walker"
+  ];
+}