man/roff.man: For roff(7), add information about the free git

package RUNOFF.git with documentation about historical RUNOFF and
the available files written in the classical RUNOFF language:
$ git clone git@github.com:RUNOFF/RUNOFF.git

1 files changed, 12 insertions, 0 deletions

diff --git a/man/roff.man b/man/roff.man
index dcf268ae..32e320ce 100644
--- a/man/roff.man
+++ b/man/roff.man
@@ -191,6 +191,18 @@ BCPL and
 were ported to the GCOS system at Bell Labs when BTL left the development of
 Multics.
 .
+.P
+There is a free
+.I git
+package at
+.I github
+consisting of the available RUNOFF documentation and RUNOFF files.
+.
+You can call it anonymously by the shell command
+.EX
+$ git clone git@github.com:RUNOFF/RUNOFF.git
+.EE
+.
 .
 .\" --------------------------------------------------------------------
 .SS "The Classical nroff/troff System"