Add flake.nix

Author: squarepear

flake.lock

@@ -0,0 +1,38 @@
+{
+  inputs = {
+    nixpkgs.url = "github:NixOS/nixpkgs/nixpkgs-unstable";
+    crane.url = "github:ipetkov/crane";
+    flake-utils.url = "github:numtide/flake-utils";
+  };
+
+  outputs =
+    {
+      nixpkgs,
+      crane,
+      flake-utils,
+      ...
+    }:
+    flake-utils.lib.eachDefaultSystem (
+      system:
+      let
+        pkgs = nixpkgs.legacyPackages.${system};
+        craneLib = crane.mkLib pkgs;
+        gdscript-formatter = craneLib.buildPackage {
+          src = ./.;
+
+          cargoExtraArgs = "--bin=gdscript-formatter";
+        };
+      in
+      {
+        packages.default = gdscript-formatter;
+
+        devShells.default = craneLib.devShell {
+          inputsFrom = [ gdscript-formatter ];
+        };
+
+        checks = {
+          inherit gdscript-formatter;
+        };
+      }
+    );
+}