feat: add multiarch devshell

flake.nix

@@ -11,12 +11,18 @@
   outputs = { self, nixpkgs, home-manager, nur, ... }@inputs: 
 let
   stateVersion = "23.11";
+  
+  allSystems = [
+    "x86_64-linux" # 64bit AMD/Intel x86
+    "aarch64-linux" # 64bit ARM macOS
+  ];
+
+  forAllSystems = fn:
+    nixpkgs.lib.genAttrs allSystems
+    (system: fn { pkgs = import nixpkgs { inherit system; }; });
 in {
-    # TODO: make a multiarch flake
-    devShells.x86_64-linux.default =
-      let 
-        pkgs = nixpkgs.legacyPackages."x86_64-linux";
-      in pkgs.mkShell {
+    devShells = forAllSystems ({ pkgs }: {
+      default = pkgs.mkShell {
         name = "nixfiles";
         buildInputs = [     
           pkgs.shellcheck
@@ -25,8 +31,8 @@ in {
           pkgs.convco
           pkgs.typos
         ];
-    };
-
+      };
+    });
     nixosConfigurations = {
       morty = nixpkgs.lib.nixosSystem {
         system = "x86_64-linux";