feat(rust): initialised cargo

flake.nix

@@ -0,0 +1,23 @@
+{
+  description = "ralsay in rust";
+
+  inputs = {
+    nixpkgs.url = "github:nixos/nixpkgs/nixos-unstable";
+  };
+
+  outputs = { self, nixpkgs }:
+  let
+    systems = [ "x86_64-linux" "aarch64-linux" ];
+    forEachSystems = nixpkgs.lib.genAttrs systems;
+    pkgsForEach = nixpkgs.legacyPackages;
+  in
+  {
+    packages = forEachSystems (system: {
+      default = pkgsForEach.${system}.callPackage ./nix/package.nix { };
+    });
+
+    devShells = forEachSystems (system: {
+      default = pkgsForEach.${system}.callPackage ./nix/shell.nix { };
+    });
+  };
+}