Adds an optional feature which displays the contents of a bookshelf when left-clicked. Sneaking must be used to destroy the bookshelf when enabled.
Updates depreciated sign code.
Bumps the API version to 1.20
Builds against 1.20
Also cleans up config stuff a bit and moves config-related tasks to its own class
Moves book loading code to its own class
Adds a default config file to make the config file have comments
Adds missing command info about the formatBook command
Adds information about required permissions to the command info
