Customizing Axes
This bar chart displays the 2018 populations of the top 10 most populous countries, with data from the UN World Population Prospects. It demonstrates how to customize D3 axes by removing default domain lines, styling tick labels and grid lines, and applying a custom tick format that converts values like 1.41G to 1.41B. The chart uses `d3.select`, `d3.csv`, `d3.scaleLinear`, `d3.scaleBand`, `d3.axisBottom`, and `d3.axisLeft`, rendering as SVG with custom title and axis labels.