Why you did not mention the name of empty wrapper?

Link

https://beta.reactjs.org/learn#writing-markup-with-jsx

In this paragraph you wrote :

JSX is stricter than HTML. You have to close tags like <br />. Your component also can’t return multiple JSX tags. You have to wrap them into a shared parent, like a <div>...</div> or an empty <>...</> wrapper:

I"d recommend to add the name of the empty Wrapper Fragment and provide the two version of it:

function AboutPage() {
  return (
    <Fragment>
      <h1>About</h1>
      <p>Hello there.<br />How do you do?</p>
    </Fragment>
  );
}

The shortcut:

function AboutPage() {
  return (
    <>
      <h1>About</h1>
      <p>Hello there.<br />How do you do?</p>
    </>
  );

}

リンク先のReact Learnページを開き、「JSX is stricter than HTML.」で始まる段落を見つけてください。Fragmentに言及し、Fragmentの明示的な構文と空タグの省略構文の両方を示すように更新してください。ページに既存のwrapperの説明とともに両方の形式が明確に示されていれば完了です。