QoL addition: Spellbook Chapters/Bookmarks

[SnowboundCabin]

Describe the feature

Allow marking a spellbook page as the first in a new chapter, putting a chapter mark before it. Chapter marks are skipped during regular scrolling, but the same key-combo as abacus precision allows scrolling between ONLY chapter marks, allowing you to name them like iota pages. Chapter marks don't count towards the 64-page limit, since they're just bookmarks. Scrolling past the end of a chapter puts the new page between it and the next one instead, so you don't have to worry about running out of space for one kind of iota before the next block of another, as well.

Additional context

Reasoning: I keep multiple small spellbooks because it's easier than scrolling 10+ pages to get to a different section, and having a bunch of blank pages between categories to give myself room to put new iotas in any particular section. I inadvisably put player references in the very back of my first book, and they're SUCH a pain to get to. I'm considering bothering the whole server to sign a different book so I don't have to scroll 50+ pages to get to them.