feat: add darwun

systems/aarch64-darwin/mercury/default.nix

@@ -0,0 +1,31 @@
+{pkgs, ...}:{
+  # List packages installed in system profile. To search by name, run:
+   # $ nix-env -qaP | grep wget
+   environment.systemPackages =
+     [ pkgs.vim
+     ];
+
+   # Auto upgrade nix package
+   nix.package = pkgs.nix;
+
+   # Necessary for using flakes on this system.
+   nix.settings.experimental-features = "nix-command flakes";
+
+   # Create /etc/zshrc that loads the nix-darwin environment.
+   programs.zsh.enable = true;  # default shell on catalina
+   programs.fish.enable = true;
+
+   # Used for backwards compatibility, please read the changelog before changing.
+   # $ darwin-rebuild changelog
+   system.stateVersion = 4;
+
+   home-manager.useGlobalPkgs = true;
+   home-manager.useUserPackages = true;
+   users.users.zack = {
+    name = "zack";
+    home = "/Users/zack";
+   };
+
+   # The platform the configuration will be used on.
+   nixpkgs.hostPlatform = "aarch64-darwin";
+}