Pdf version of Groovy single-page documentation on web site

There is Single-Page document on web site in html format:
http://groovy-lang.org/single-page-documentation.html
It would be wonderful to have the same doc in pdf format and place the link to it on the groovy site.
Pdf is much easier to use on e-ink readers, ipads, etc.

This gradle example shows how to achieve this:
https://github.com/asciidoctor/asciidoctor-gradle-examples/blob/master/asciidoc-to-pdf-example/build.gradle