ggvis cookbook has a typographic error

[libjohn]

The boxplot section (at the bottom) of the ggvis cookbook is not rendering properly.

The heading is listed in the rendered HTML as:

Box plots

And there is no table of contents section at the top of the page for the boxplot section.

I'm not sure where to report this. I found no "contact" info on the ggivs page. Maybe identifying this as an issue here in github will further the message along.