chore: add nix derivation

flake.nix

@@ -0,0 +1,31 @@
+{
+  description = "Rust bindings for libnotify";
+
+  inputs = {
+    nixpkgs.url = "nixpkgs/nixos-unstable";
+    flake-parts.url = "github:hercules-ci/flake-parts";
+  };
+
+  outputs =
+    inputs@{ flake-parts, ... }:
+    # https://flake.parts/module-arguments.html
+    flake-parts.lib.mkFlake { inherit inputs; } ({
+      flake = {
+        # Put your original flake attributes here.
+      };
+
+      systems = [
+        "x86_64-linux"
+      ];
+
+      perSystem = { config, pkgs, ... }: {
+        # Recommended: move all package definitions here.
+        # e.g. (assuming you have a nixpkgs input)
+        # packages.foo = pkgs.callPackage ./foo/package.nix { };
+        # packages.bar = pkgs.callPackage ./bar/package.nix {
+        #   foo = config.packages.foo;
+        # };
+        packages.default = pkgs.callPackage ./package.nix { };
+      };
+    });
+}