Fork of Smiley Face Part-3 (React and d3)
This example shows a smiling face built as an SVG component, composed of a yellow circle for the head, two dark circles for eyes, and a curved arc for the mouth. The face is rendered in React using SVG elements, with the mouth generated by the `arc` helper from the d3-shape package, which defines inner and outer radii plus start and end angles. A group element centers all parts via a translate transform, and the entire face is drawn with fixed numeric constants for dimensions and offsets.