You have two different options to download this user guide for offline use:
Export to PDFicon on the right sidebar will generate a PDF file of the current page and offer it for downloading.
Add to bookicon on the right sidebar will add the currently shown page to a list of pages to be downloaded.
While having an offline version of this user guide can be helpful, please keep in mind that the contents of the online version might be changed, corrected and enhanced from time to time. Your offline version might become outdated sooner or later.