Making a Bar Chart
This example builds a bar chart of country populations from a CSV file. It uses D3 v5 methods such as `d3.csv`, `scaleLinear`, and `scaleBand` to map population values to screen coordinates, while `select` and `data` joins append SVG rectangles for each country. The chart renders with a 960-by-500 SVG canvas, and the code includes placeholder ranges and dimensions that are not fully implemented.