add creamlinux-installer package

nixos/gaming.nix

@@ -54,6 +54,7 @@
     })
     # (pkgs.callPackage ../packages/ftb-app.nix { inherit pkgs; })
     (pkgs.callPackage ../packages/svc.nix { inherit pkgs; })
+    (pkgs.callPackage ../packages/creamlinux-installer.nix { inherit pkgs; })
     lunar-client
     stablePkgs.heroic
     dolphin-emu

packages/creamlinux-installer.nix

@@ -0,0 +1,32 @@
+{ pkgs }:
+
+pkgs.stdenv.mkDerivation rec {
+  pname = "creamlinux";
+
+  src = pkgs.fetchFromGitHub {
+    owner = "Novattz";
+    repo = "creamlinux-installer";
+    rev = "f9e7c2f614d45d3c286692ea9f0356788c515103";
+    sha256 = "sha256-wOzNE6PsGhRsWBuIVQPN/5+aKjl0Gq45qLrL6DceLDM=";
+  };
+
+  propagatedBuildInputs = [
+    (pkgs.python3.withPackages (
+      pythonPackages: with pythonPackages; [
+        requests
+        rich
+      ]
+    ))
+  ];
+
+  dontUnpack = true;
+  installPhase = ''
+    install -Dm755 ${./main.py} $out/bin/${pname}
+  '';
+
+  meta = {
+    description = "A user-friendly tool for managing DLC for Steam games on Linux systems.";
+    homepage = "https://github.com/Novattz/creamlinux-installer";
+    maintianers = "cswimr";
+  };
+}