Replace instances of blank line paragraphing with `PP` macro calls.
There are three problems with the style of paragraphing that this commit
fixes.
1. A `br` break request is redundant with an adjacent blank text line.
2. A `br` request is also redundant with a paragraphing macro call.
3. When you use a paragraphing macro call instead of a blank text line,
you get the configured amount inter-paragraph space. When
typesetting with the man(7) package, the default inter-paragraph
space amount is 0.4v. A blank text line usually puts 1v of empty
space into the document.
See groff_man_style(7).
Fixes:
$ nroff -ww -z -rCHECKSTYLE=4 -man doc/*.[67]
an.tmac:doc/nethack.6:435: style: blank line in input
an.tmac:doc/nethack.6:442: style: blank line in input
an.tmac:doc/nethack.6:535: style: blank line in input
an.tmac:doc/nethack.6:539: style: blank line in input
an.tmac:doc/nethack.6:543: style: blank line in input
an.tmac:doc/nethack.6:568: style: blank line in input
an.tmac:doc/nethack.6:572: style: blank line in input
G. Branden Robinson
c91ee79dcb