Fork of Let's make a map with D3.js!
A yellow smiley face with animated eyebrows demonstrates basic D3.js DOM manipulation. The face is drawn using SVG shapes: a circle for the head, circles for eyes, a path with `d3.arc()` for the mouth, and rectangles for eyebrows. D3’s `transition()` method moves the eyebrow group vertically over 2000 milliseconds, creating a continuous up-and-down motion. The code selects the SVG element, appends groups with `translate` transforms, and positions all facial features relative to the canvas center using fixed pixel offsets.