"Documentation Theme" is a great usability improvement. Now it's much easier to read created documents. But I'd like to propose small improvement:

When you open a page, it marked as bold at the left navigation tree. It would be very nice to expand this bold node and show child pages automatically. It will help to go to the next page even if you haven't a link to it at the open page. So it will not be necessary to create an index, toc or list of children at any parent page and it will make Space exported to PDF much more readable.