React getting started - React.StrictMode

Hi,
I’m reading the Getting started with React atricle.
Just in the beginning of the Interrogating the index section there is a desription about src/index.js
Instead of this line of code:
ReactDOM.render(<App />, document.getElementById('root'));
I got this:

ReactDOM.render(
  <React.StrictMode>
    <App />
  </React.StrictMode>,
  document.getElementById('root')
);

just notifying…

@Rafael_Green I agree that we should try to keep these details up-to-date as much as possible. I’ve updated the article to suit. Thanks!