add missing copyright info

doc/dlb.6

@@ -1,6 +1,17 @@
-.TH DLB 6 "28 Oct 1993"
-.\" NetHack 3.6  dlb.6	$NHDT-Date: 1432512786 2015/05/25 00:13:06 $  $NHDT-Branch: master $:$NHDT-Revision: 1.6 $
-.UC 4
+.TH DLB 6 "25 May 2015" NETHACK
+.de ND
+.ds Nd \\$3
+..
+.de NB
+.ds Nb \\$2
+..
+.de NR
+.ds Nr \\$2
+..
+.ND $NHDT-Date: 1524689548 2018/04/25 20:52:28 $
+.NB $NHDT-Branch: NetHack-3.6.0 $
+.NR $NHDT-Revision: 1.7 $
+.ds Na Kenneth Lorber
 .SH NAME
 dlb \- NetHack data librarian
 .SH SYNOPSIS
@@ -92,3 +103,7 @@ Not a good tar emulation; - does not mean stdin or stdout.
 Should include an optional compression facility.
 Not all read-only files for NetHack can be read out of an archive;
 examining the source is the only way to know which files can be. 
+.SH COPYRIGHT
+This file is Copyright (C) \*(Na and was last modified \*(Nd (version
+\*(Nb:\*(Nr).
+NetHack may be freely redistributed.  See license for details.