Fork of Let's Make a Face Part I
This example draws a simple, static smiley face using React and D3.js. A yellow circle forms the head, with two black eyes positioned symmetrically on either side of the center, and a mouth generated with the `d3.arc()` path generator. All shapes are rendered as SVG elements within a single `<g>` transform that centers the coordinate system, with the face’s dimensions derived from the viewport height and stroke width. The code uses D3 v6 for the arc path and React for component-based markup.