Let me know if it makes more sense to make a new book-chapter-location procedure rather than modifying book-location.
Made a change to book-location so it can be used as the location of a…
… book chapter.
Yes, I think a new `book-chapter-location' would be better, since it took me a while to understand the intent of the change (and then I understood why you suggested an alternate procedure).
@elibarzilay This can be closed, @ianj says that he'll create a new PR for this when revised.