add nix-darwin

[DannyDannyDanny]

Switching back to macbook with MacOS. Documenting how I configured / installed nix on mac on this issue for. Vaguely inspired by Fatih Altinok. To be moved to README.md 🚚

1. git clone https://github.com/DannyDannyDanny/dotfiles.git
2. install nix via DeterminateSystems/nix-installer - ⚠️ use MacOS package.
3. Write MacOS config: https://github.com/DannyDannyDanny/dotfiles/pull/12/files based on https://github.com/nix-darwin/nix-darwin?tab=readme-ov-file

[DannyDannyDanny]

Tips from @plasmagoat

• (system.defaults.finder)
  • apple show all extensions
  • apple show all files
• security.sudo.extraconfig -> passwordless sudo
  security.sudo.extraConfig = "${userConfig.name} ALL = (ALL) NOPASSWD: ALL";