Smiley Face Part IV
This example renders a static “Hello World” message as a React component, serving as a minimal starter template. The code imports React and ReactDOM to mount the `<App />` element into a `#root` div, using React 16.9 UMD builds loaded from unpkg. The visualization itself is absent; instead, it demonstrates the basic structure for a React-based page, though no data or charting library is employed.