nixos/modules/system/spell-check/default.nix

# spell-checking
{ config, lib, options, pkgs, ... }:
let
  cfg = config.my.system.spell-check;
in
{
  options.my.system.spell-check = with lib; {
    enable = mkEnableOption "spell-check configuration";
  };

  config = lib.mkIf cfg.enable {
    environment.systemPackages = with pkgs; [
      aspell
      aspellDicts.en
      aspellDicts.en-computers
      aspellDicts.en-science
    ];
  };
}