The Bookshelf library contains a number of useful functions for modders. It was originally created for Forge, but later a Fabric version was released. This library is used by more than 50 mods, so you can often see it in the installation instructions. There is no point in downloading it separately since it does not contain any new content for the game.
How to install Bookshelf Library
- Make sure you have installed Fabric Mod Loader and Fabric API or Quilt.
- Download the mod for your version of the game.
- Put it in the ‘mods’ folder, which is located in the game folder.