[Groff] add extra footer with running page numbers

[Jeremy C. Reed]

Can someone please point me to documentation or provide an example of 
adding an extra footer with page numbers?

The postscript document is made of many man files using tbl, troff and 
grops. Currently it has the page numbering of each individual 
documentation (so restarts on page 1 very frequently). I'd like to have a 
running page number for entire postscript document too or instead.

Or should I use psutils, a2ps or other tool to post process?