message: fix: document yarn flag
diff: @@ -5,7 +5,7 @@ import Base from './command_base'
  export default abstract class AppCommand extends Base {
  static flags = {
  defaults: flags.boolean({description: 'use defaults for every setting'}),
  - options: flags.string({description: '(typescript|tslint|semantic-release|mocha)'}),
  + options: flags.string({description: '(yarn|typescript|tslint|semantic-release|mocha)'}),
  force: flags.boolean({description: 'overwrite existing files'}),
  }
  static args = [
  