html_write:layout/3

Define required newlines before and after tags. This table is rather incomplete. New rules can be added to this multifile predicate.

Arguments:

`Tag`	- Name of the tag
`Open`	- Tuple M-N, where M is the number of lines before the tag and N after.
`Close`	- Either as `Open`, or the atom - (minus) to omit the close-tag or `empty` to indicate the element has no content model.

To be done

- Complete table