Let's refactor based on the template, maybe this works

flake.nix

@@ -50,7 +50,25 @@
     ...
   } @ inputs: let
     inherit (self) outputs;
+    # Supported systems for your flake packages, shell, etc.
+    systems = [
+      "armv7l-linux"
+      "x86_64-linux"
+    ];
+    # This is a function that generates an attribute by calling a function you
+    # pass to it, with each system as an argument
+    forAllSystems = nixpkgs.lib.genAttrs systems;
   in {
+    # Your custom packages
+    # Accessible through 'nix build', 'nix shell', etc
+    packages = forAllSystems (system: import ./pkgs nixpkgs.legacyPackages.${system});
+    # Formatter for your nix files, available through 'nix fmt'
+    # Other options beside 'alejandra' include 'nixpkgs-fmt'
+    formatter = forAllSystems (system: nixpkgs.legacyPackages.${system}.alejandra);
+
+    # Your custom packages and modifications, exported as overlays
+    overlays = import ./overlays {inherit inputs;};
+
     # NixOS configuration entrypoint
     # Available through 'nixos-rebuild --flake .#your-hostname'
     nixosConfigurations = {