Datapack Manual
adds a handy documentation book that other datapacks can add pages to. All my datapacks have Datapack Manual pages.
To craft a Datapack Manual, just sign a book and quill with the title "Datapack Manual".
If you make datapacks, you can add a page to the Datapack Manual! Just make a function of the form:
data modify entity @s Item.tag.pages append value '[ARRAY OF JSON TEXT COMPONENTS]'