Smiley Face Part II
A yellow smiley face with black-outlined eyes and a mouth is drawn as a static SVG. The face is centered on a 960 by 500 canvas, built from three circles and an arc path created with the `d3.arc()` API. The React component `App` renders the SVG tree, and the face is composed using hard-coded dimensions for offsets, radii, and stroke widths. The example demonstrates combining React’s declarative JSX with D3’s shape generators for a simple decorative visualization.