Making a Bar Chart
This bar chart displays the population of the top 10 most populous countries, using 2018 estimates from the United Nations World Population Prospects. It demonstrates how to customize D3 axes, including a custom tick format that abbreviates large numbers with the `format('.3s')` method and replaces 'G' with 'B'. The visualization uses `d3.csv` to load data, `scaleLinear` and `scaleBand` for scaling, and `axisLeft` and `axisBottom` to render the axes. The chart is rendered as SVG with steelblue bars and labeled axes.