Smiling Face w/ JS, React, and D3
A smiling face composed of a yellow circle, two black eyes, and an arc-shaped mouth is rendered as an SVG. The example demonstrates how to build reusable chart components with React and D3, using the `arc()` generator from `d3` to construct the mouth path. Static values for dimensions and positions are defined in `index.js`, and React components such as `BackgroundCircle`, `Eyes`, and `Mouth` receive these as props to render the final graphic.