do we need page-related metadata in the non-visual reading book?

[marisademeglio]

Ace reports that there should be a pagelist when the accessibility metadata includes pageBreakMarkers. The non-visual reading book has this metadata but does not have a pagelist. I think we should remove pageBreakMarkers.

Also the accessibility metadata includes pageNavigation, which does not raise an Ace violation, but I don't see how it makes sense in this publication. None of the techniques described in EPUB Accessibility 1.1 Page Navigation would apply here as there are no static page markers anywhere in the book.

cc @GeorgeKerscher

[marisademeglio]

Page metadata also removed here
#92