Fork of Let's make a face with D3.js!
A smiley face rendered as SVG shapes animates its eyebrows up and down in a two-second cycle. The face uses D3.js v5 to construct a yellow circle, two eyes, rectangular eyebrows, and a mouth path via `d3.arc()` with specified inner and outer radii and angle ranges. The animation drives the eyebrow group's transform attribute through sequential `transition().duration(2000)` calls, moving it vertically and back. The code also demonstrates DOM manipulation by appending elements to an SVG container, using fixed pixel coordinates and attribute setters.