configureHelp(configuration) {
    if (configuration === undefined) return this._helpConfiguration;

    this._helpConfiguration = configuration;
    return this;
  }
You can customise the help by overriding Help properties using configureHelp(),
or with a subclass of Help by overriding createHelp().

@param {object} [configuration] - configuration options
@return {(Command | object)} `this` command for chaining, or stored configuration