man: Document changes to firewall_type allowing a directory

Signed-off-by: Dan Mahoney <[email protected]>

Author: thegushi

share/man/man5/rc.conf.5

@@ -692,7 +692,11 @@ basic protection for a LAN.
 .El
 .Pp
 If a filename is specified, the full path
-must be given.
+must be given.  If a directory is specified, then
+the directory should contain files containing headers
+compatible with rcorder(8) as they will be sorted
+in this order, and then ipfw(8) will be run on each,
+as though each were a singular rules file.
 .Pp
 Most of the predefined rulesets define additional configuration variables.
 These are documented in