TypeScript Error

App.tsx

// This React app contains a type-related error.
// Please find it and explain how you would fix it.

import React, { ReactElement } from 'react';
import './App.css';

function Heading({ title }: { title: string }) {
  return <h1>{title}</h1>;
}

function Container({ children }: { children: string }): ReactElement {
  return <div>{children}</div>;
}

function App() {
  return (
    <div>
      <Container>
        <Heading title="Welcome!"></Heading>
        <p>Stay a while.</p>
      </Container>
    </div>
  );
}

export default App;