- disallow moving from custom shelf to a reading status shelf with shelf_selector
- always use shelve_button for moving books from a reading status shelf
- redesign shelf information as a list of boxes
- Wrap block level elements within block level elements, not inline.
- Avoid empty blocks.
- Change `<hr>` in lists into allowed type of children.
- Fix duplicated ID (some change that was not propagated across the template?).
- Make the anchor optional in the navbar (interactive elements (`a`, `input`, `button`…) should not appear into other interactive elements).
- Remove redundant `role` on main navigation.
- Make the modal a modal with `role="dialog".
- Use `button` instead of form-less `label`.
