Leader lines for line chart

[jtrim-ons]

trafficstars

Our World in Data has a nice way to label the series in a line chart.

I've tried to implement something similar here.

I haven't yet figured out what to do if some data points are missing.

Would the leader line thing be useful for a template?

[jtrim-ons]

If we do this, it might be a good idea to make the lines look exactly like the Our World in Data lines. Their code is open source.