title: React - cannot be used as a JSX component. Its return type 'void' is not a valid JSX element
body: <p>I have a <a href="https://stackblitz.com/edit/react-ts-tbn72b" rel="noreferrer">stackblitz demo here</a></p>
  <p>It's a super simple app that should just show an input with test below and the output of whats been put into the input field.</p>
  <p>I'm getting an error on the input component</p>
  <pre><code>'CustomInput' cannot be used as a JSX component.
    Its return type 'void' is not a valid JSX element.
  </code></pre>
  <p>Can anyone see why I'm getting this error</p>