This manual is itself a GRAV site, built on a GRAV theme called Learn2. This is the way that GRAV presents its own documentation.
The PNHB manual is a subdomain on our web server - the web address of the manual is "rtfm.nhbpeterborough.com/admin" - Read The Flaming Manual:)
The manual can be edited RTFM. This is a GRAV admin and navigated the same way as the PNHB website. The structure is just chapters and sections. Chapters and sections are themselves pages to be edited the same way as the website.
The reader sees an outline in the left panel and can open chapters and sections by clicking them there.
In the main panel, the big right arrow moves to the next section and the left goes back to the outline.