We don’t currently “build” an html version of the documentation — the version located at https://www.rosettacommons.org/docs/latest/Home is being served live by a Gollum wiki server (in no-edit mode) from the markdown documents in the Rosetta/documentation/ directory which comes with the Rosetta download.
You should be able to install a Gollum server locally to serve the pages for a webbrowser running on your machine. See https://github.com/gollum/gollum/wiki/Installation for more information on installation. (If you have administrator access, gollum should be availible through most Linux distributions.)
Note that we have some minor local modifications to the gollum server, so there may be some slight rendering differences between the online version and the locally served one.