Smiley Face
This example renders a yellow smiley face as a React component using SVG. It draws a filled circle for the head, two smaller circles for the eyes, and a mouth created with the `arc` function from `d3`. The arcs are positioned by translating the coordinate system to the center of the 960×500 canvas. The code uses `ReactDOM.render` to mount the component and applies static stroke and fill colors without any interaction or animation.