

Wouldn’t a word processor do trick? you can add links, images, refs, notes,… and have as many pages as you need (edit: and search them, add a table of content, and so on). LIbreOffice is most certainly already installed on your Linux distro and is also available for Mac and Windows.
I may have missed something, here so to make sure:
It can also help you write the actual book, worrying about the document ‘look’ aka its formatting is optional (and if done properly, using Styles, it’s almost 100% automated) ;)