Tidy manuals/show page

- Add padding between buttons when they are collapsed
- Remove "Manual title" label as I think this is pretty obviously the title and doesn't require labelling
- Make link disabled when the manual hasn't been published as it 404's otherwise.
- Add a message for when there aren't any sections yet and a call to action next to the message
Tidy sections/new

- Change title from the manual title to "Add a new section" as this is better explains what the page does
- Make the input[type=text] box and text area boxes have the same border and padding
- Fix label alignment on minor update box