nixos/modules/options/shell.nix

{
  config,
  lib,
  ...
}:
with lib;
let
  cfg = config.modules.shell;
in
{
  options.modules.shell = {
    defaultShell = mkOption {
      type = types.enum [
        "bash"
        "zsh"
      ];
      default = "zsh";
      description = ''
        The default shell to use for your user account.
      '';
    };
  };
}