Fix typo in the User Guide (#3670)

Replace `provide a lot value` with `provide a lot of value`.

Author: qbahers

packages/react-scripts/template/README.md

@@ -1258,7 +1258,7 @@ it('renders without crashing', () => {
 });
 ```
 
-This test mounts a component and makes sure that it didn’t throw during rendering. Tests like this provide a lot value with very little effort so they are great as a starting point, and this is the test you will find in `src/App.test.js`.
+This test mounts a component and makes sure that it didn’t throw during rendering. Tests like this provide a lot of value with very little effort so they are great as a starting point, and this is the test you will find in `src/App.test.js`.
 
 When you encounter bugs caused by changing components, you will gain a deeper insight into which parts of them are worth testing in your application. This might be a good time to introduce more specific tests asserting specific expected output or behavior.