Missing AreaY example in docs

[gvanhorne]

Plot Area Mark documentation refers to a missing example

Expected Behavior

Either show an example where the baseline of an area chart is y = 0, or remove reference to the area chart of Apple's stock price.

Current Behavior

No example is provided.

Steps to reproduce

1. Goto https://observablehq.com/plot/marks/area#areaY
2. Verify whether an example is provided

[mbostock]

The example is shown at the top of the page:

Plot.areaY(aapl, {x: "Date", y: "Close"}).plot()

I’ll delete this errant sentence that’s remains from moving content around. Thanks for the report!