• Can we support this per-category?
• Or just per-book?

Use search screen logic/layout for index rendering

• Route all state changes (open/close book, category, entry) through gui manager?
• Book Overview Screen variant that is index-based
  • search button
  • Optional description for the first page of the book index screen
  • read all button
• Book Category Screen that is index-based
  • Optional description for the first page of a category's index
• For books with a node overview screen but index categories, create a dummy node category screen to render as a background
  • Important: Figure out a way to enable category navigation. E.g. in fabric we currently do not have multi gui layers
• add proper gui layers to fabric?
• Check TODO comments in code
• reduce datagen obligations for index-only books
  • don't need entry parents (probably not mandatory anyway currently)
  • auto-set category mode to index? -> the book is doing this automatically now independent of the data
• allow to specify entry order
  • add internal counter to datagen for default order?
• refactor gui package to be organized by node vs index instead of parent/category?
• Test JEI gui integration and restoring -> no JEI yet
• Check and test search screen & screen state/stack handling
• update docs