A heavily extended version of an API from ocular_networks, guidebooks is a library mod which allows the creation of in-game documentation in the form of an item.
This item is called a 'book' internally (although it doesn't have to be a book to the user) and will open a formspec when used.
This formspec is easy to create, as you only need a width, height, and background image.
Each book can hold up to 28 'sections' which can hold pages, or subsections.
subsections can only hold pages.
pages are defined using two text fields but also support the use of a custom formspec string.
(This mod doesn't add any content on its own other than an example book)
license of media and source: CC-BY-SA 4.0