Include in whisker.render documentation of triple mustache usage ({{{...}}})

[Christopher Brown]

I did not know about the usage of triple mustaches for unescaping. I struggled with it a bit until I found:
http://stackoverflow.com/questions/20323351/how-to-disable-html-characters-escaping-in-whisker-render-in-r

Which answered my question. It would be nice if this was more prominent in the documentation such as that for the package or in whisker.render

[Edwin de Jonge]

Thanks for the suggestion: at the moment it is also described as a note in https://github.com/edwindj/whisker, but I will add it to the R-documentation of whisker.