feat(flake): add hetch to packages output

flake.nix

@@ -4,13 +4,14 @@
     nixpkgs.url = "github:NixOS/nixpkgs/nixos-unstable";
     treefmt.url = "github:numtide/treefmt-nix";
   };
-  outputs =
-    inputs@{ nixpkgs, ... }:
-    let
+  outputs = inputs @ {
+    self,
+    nixpkgs,
+    ...
+  }: let
     inherit (nixpkgs) lib;
     systems = ["x86_64-linux"];
-      forAllSystems =
-        f:
+    forAllSystems = f:
       lib.genAttrs systems (
         system:
           f {
@@ -20,18 +21,16 @@
           }
       );
     treefmtEval = forAllSystems ({pkgs}: inputs.treefmt.lib.evalModule pkgs ./flake/treefmt.nix);
-    in
-    {
+  in {
     packages = forAllSystems (
-        { pkgs }:
-        {
+      {pkgs}: {
         default = pkgs.callPackage ./flake/package.nix {};
       }
     );
     devShells = forAllSystems (
-        { pkgs }:
-        {
+      {pkgs}: {
         default = pkgs.callPackage ./flake/shell.nix {};
+        hetch = self.packages.${pkgs.system}.default;
       }
     );
     formatter = forAllSystems ({pkgs}: treefmtEval.${pkgs.system}.config.build.wrapper);