Fix part of the SYNOPSIS documenting LIST OF RULES AND PREPROCESSING

that is still referred as last section of the SYNOPSIS later
but was erroneously situated in the section IN-KERNEL NAT.

MFC after:	1 month

sbin/ipfw/ipfw.8

@@ -1,7 +1,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd November 12, 2018
+.Dd November 13, 2018
 .Dt IPFW 8
 .Os
 .Sh NAME
@@ -105,16 +105,6 @@ in-kernel NAT.
 .Ar number
 .Cm config
 .Ar config-options
-.Pp
-.Nm
-.Op Fl cfnNqS
-.Oo
-.Fl p Ar preproc
-.Oo
-.Ar preproc-flags
-.Oc
-.Oc
-.Ar pathname
 .Ss STATEFUL IPv6/IPv4 NETWORK ADDRESS AND PROTOCOL TRANSLATION
 .Nm
 .Oo Cm set Ar N Oc Cm nat64lsn Ar name Cm create Ar create-options
@@ -166,6 +156,16 @@ in-kernel NAT.
 .Cm internal talist
 .Nm
 .Cm internal vlist
+.Ss LIST OF RULES AND PREPROCESSING
+.Nm
+.Op Fl cfnNqS
+.Oo
+.Fl p Ar preproc
+.Oo
+.Ar preproc-flags
+.Oc
+.Oc
+.Ar pathname
 .Sh DESCRIPTION
 The
 .Nm