It certainly would be nice if there was a single-file downloadable/printable file in PDF or HTML that covers the Help documentation.
I would like to be able to search for a term across the help documentation, but that’s impossible without opening every HTML file in it, and I also often use the program when I’m not online.
If you install the recommended version of Audacity then you will have the manual installed locally. See: Audacity 2.1.1 installer (24.0 MB, includes help files) http://web.audacityteam.org/download/windows
There are about 340 pages to the manual, so it is far too large for a single HTML file. To date we have not found a html to pdf converter that is able to convert the manual accurately to pdf format without a great deal of manual editing (which we don’t have the resources to do). Audacity is free, open source software, brought to you by a small group of enthusiasts from around the world. Feel free to contribute (http://web.audacityteam.org/community/ and/or http://web.audacityteam.org/donate/)