Fork of Let's Make a Face Part I
This example shows a simplified smiley face drawn with SVG shapes: a yellow circle for the head, two black circles for eyes, and a curved mouth path. The mouth is created using the `d3.arc()` generator with inner and outer radii and start/end angles. The code uses React for component structure and rendering, while D3 v7 provides the arc calculation. The face is centered within a 960×500 viewport, with fixed positions for facial features based on defined offsets and dimensions.