Let's start working with D3
This example demonstrates a minimal React application that renders a static heading element. The code uses React and ReactDOM to mount an `App` component, which returns a single `<h1>` tag displaying the text "Akim". The heading is styled with the CSS class `.heading`, which has its visibility set to hidden, so the text is not visible on the page. The example uses the production builds of React 16.12.0 and ReactDOM, served from unpkg, and includes an external stylesheet. It serves as a starting point for integrating React with D3 visualizations.