Making a Bar Chart
This bar chart displays the populations of the top ten most populous countries, using 2018 estimates from the United Nations World Population Prospects. The visualization uses D3 v5, with `d3.scaleLinear` mapping population values to bar widths and `d3.scaleBand` positioning countries along the vertical axis. Bars are rendered as SVG rectangles with a steelblue fill. The data is loaded from a CSV file and parsed before being passed to the render function.