Support for Radar Charts

[isaacabraham]

I'm trying to achieve something like this in Plotly. However, I can't see how to do it:

• Using a Scatter chart with a Radial axis gets close, but the scatter on the axis isn't "closed" (even if you set fill on the Scatter to toself).
• Using an Area isn't doesn't have the correct output.

It seems we need to generate a "scatterpolar" which I can't see anywhere in XPlot.Plotly.