added nix shell

shell.nix

@@ -0,0 +1,25 @@
+let
+  unstableTarball = fetchTarball https://github.com/NixOS/nixpkgs/archive/nixos-unstable.tar.gz;
+  pkgs = import <nixpkgs> {}; 
+  unstable = import unstableTarball {};
+
+  shell = pkgs.mkShell {
+    depsBuildBuild = with unstable; [
+      pkg-config
+    ];
+
+    nativeBuildInputs = with unstable; [
+      cmake meson ninja pkg-config wayland-scanner scdoc
+    ];
+
+    buildInputs = with unstable; [
+      wayland libxkbcommon pcre json_c libevdev
+      pango cairo libinput libcap pam gdk-pixbuf librsvg
+      wayland-protocols libdrm wlroots dbus xwayland
+
+      # wlroots
+      libGL pixman xorg.xcbutilwm xorg.libX11 libcap xorg.xcbutilimage xorg.xcbutilerrors mesa
+      libpng ffmpeg xorg.xcbutilrenderutil seatd
+    ];
+  };
+in shell