This example presents a blank React + D3 starter template that establishes the foundational structure for a visualization. It uses CDN-loaded React 16.13.1, ReactDOM, and D3 v6.2.0 to render an SVG via the `VizContainer` component, which applies the margin convention and abstracts the outer and inner rectangle elements. The code defines explicit width, height, and margin variables, and the component conditionally displays the margins based on a `showMargins` prop. The rendered output is an empty SVG with grey and light-grey rectangles, ready for chart content.