feature request: automatic chapter numbering

[ThiloWitt]

It would be helpful to get automatic chapter and sub-chapter numbering like there was in Jorn's book module => this would empower Content to become a book module.

The numbering should include pages, sub-pages and the headings contained in them and reflect their hierarchy.

There should be a selector to switch numbering on/off for a page and its sub-pages. If a mother-page has numbering = on, its child-page should have that option greyed out and be forced to numbering.

The numbering should appear in front of headings and page titles - but not in bread crumbs nor short-urls. They should not be editable and only depend on the position of a child-page or heading.

The numbering should also be visible in the table of contents.