feat: use local packwiz package

nix/packwiz.nix

@@ -0,0 +1,41 @@
+{
+  lib,
+  buildGoModule,
+  fetchFromGitHub,
+  installShellFiles,
+  unstableGitUpdater,
+}:
+
+buildGoModule {
+  pname = "packwiz";
+  version = "0-unstable-2024-10-15";
+
+  src = fetchFromGitHub {
+    owner = "packwiz";
+    repo = "packwiz";
+    rev = "0626c00149a8d9a5e9f76e5640e7b8b95c064350";
+    sha256 = "sha256-eAGfLUcyjDR2oJjLK3+DiuICTqoOcIwO5wL350w6vGw=";
+  };
+  passthru.updateScript = unstableGitUpdater { };
+
+  vendorHash = "sha256-krdrLQHM///dtdlfEhvSUDV2QljvxFc2ouMVQVhN7A0=";
+
+  nativeBuildInputs = [
+    installShellFiles
+  ];
+
+  postInstall = ''
+    installShellCompletion --cmd packwiz \
+      --bash <($out/bin/packwiz completion bash) \
+      --fish <($out/bin/packwiz completion fish) \
+      --zsh <($out/bin/packwiz completion zsh)
+  '';
+
+  meta = with lib; {
+    description = "Command line tool for editing and distributing Minecraft modpacks, using a git-friendly TOML format";
+    homepage = "https://packwiz.infra.link/";
+    license = licenses.mit;
+    maintainers = with maintainers; [ infinidoge ];
+    mainProgram = "packwiz";
+  };
+}