x11/xkbutils: improve comment, add upstream url

Reported by:	concussious.bugzilla_runbox.com
Approved by:	x11 (maintainer, timeout)
Differential Revision:	https://reviews.freebsd.org/D45408

x11/xkbutils/Makefile

@@ -3,7 +3,8 @@ PORTVERSION=	1.0.6
 CATEGORIES=	x11
 
 MAINTAINER=	x11@FreeBSD.org
-COMMENT=	XKB utility demos
+COMMENT=	Collection of small X Keyboard Extension utilities
+WWW=		https://gitlab.freedesktop.org/xorg/app/xkbutils
 
 LICENSE=	MIT