Dead API link in windVectors.md example

[dsmedia]

While working on vega/vega-datasets#663, I noticed that the windVectors.md example contains a dead API link for accessing the gridded global wind data (https://data.planetos.com/datasets/rss_ccmp_winds_v2).
Would it be possible to update this with a current link to access the wind data?

Thanks @jwoLondon for maintaining these educational resources!