Temperature San Fransisco Line Chart
This line chart displays a week of temperature data from multiple cities around the world, with each city represented by a colored line plotted over time. The visualization uses D3 v5 to load CSV data, scales time and temperature with `scaleTime` and `scaleLinear`, and renders the lines with `line`, `curveBasis`, and `nest` for grouping. A color legend, built with a custom `colorLegend` function, maps city names to ordinal colors, while axes and labels are added using `axisLeft` and `axisBottom`.