We should be able to group pages and collapse them, for a cleaner more organized flow.

My use case - I'm working on a book (not using the "create book" option since it's exteremly flawed) that has an intro of 50 pages.
I'm done designing those 50 pages, and now I want to "forget" about them and collapse them, so I can focus on other pages, and also get to them quicker without needing to scroll through all those pages.

This could be done by grouping the intro and having the option to collapse it, or by adding the collapse option to the already-set intro section.

I added an example of what a collapsed group can look like (pages 17 to 21. the document is RTL).

Thank you!