Making a Bar Chart
This bar chart displays the top 10 most populous countries in 2018, based on United Nations World Population Prospects 2017 data, with populations multiplied by 1,000. It uses D3 v5 with SVG rendering, employing `d3.scaleLinear` for the x-axis and `d3.scaleBand` for the y-axis. The chart customizes axes with `d3.axisLeft` and `d3.axisBottom`, formats tick labels via `d3.format`, and includes grid lines, a title, and an axis label.