docs: add comment about 'cleanup' in react-testing-library exam… (#9144)

Author: newtonry

docs/TutorialReact.md

@@ -256,7 +256,8 @@ import React from 'react';
 import {cleanup, fireEvent, render} from '@testing-library/react';
 import CheckboxWithLabel from '../CheckboxWithLabel';
 
-// automatically unmount and cleanup DOM after the test is finished.
+// Note: running cleanup afterEach is done automatically for you in @testing-library/[email protected] or higher
+// unmount and cleanup DOM after the test is finished.
 afterEach(cleanup);
 
 it('CheckboxWithLabel changes the text after click', () => {

examples/react-testing-library/__tests__/CheckboxWithLabel-test.js

@@ -4,7 +4,8 @@ import React from 'react';
 import {cleanup, fireEvent, render} from '@testing-library/react';
 import CheckboxWithLabel from '../CheckboxWithLabel';
 
-// automatically unmount and cleanup DOM after the test is finished.
+// Note: running cleanup afterEach is done automatically for you in @testing-library/[email protected] or higher
+// unmount and cleanup DOM after the test is finished.
 afterEach(cleanup);
 
 it('CheckboxWithLabel changes the text after click', () => {