To be honest, even if we'd love to have an offline documentation, this is not a current priority.
I wouldn't say it's a difficult task, but I would say it's time consumming. First of all, we can't simply select the entire doc, and copy paste it. In addition, many formats from the online doc won't be supported in a .PDF, and everything has to be rearranged for the document.
It also means that we always have to update two different doc, one online and one offline.
As mentionned, not a tremendo
...