message: docs: update identity-revealed.directive.ts to use `AbstractControl` instead of `FormGroup`
  Changes example code to accept an `AbstractControl` instead of `FormGroup` in
  `identityRevealedValidator` function.
  Closes
  PR Close
diff: @@ -4,7 +4,7 @@ import { AbstractControl, FormGroup, NG_VALIDATORS, ValidationErrors, Validator,
  // #docregion cross-validation-validator
  /** A hero's name can't match the hero's alter ego */
  -export const identityRevealedValidator: ValidatorFn = (control: FormGroup): ValidationErrors | null => {
  +export const identityRevealedValidator: ValidatorFn = (control: AbstractControl): ValidationErrors | null => {
  const name = control.get('name');
  const alterEgo = control.get('alterEgo');
  