directfb: add help text to Config.in, note broken URL

Adds descriptive help text to Config.in based on content from elinux.org and
Wikipedia. Notes that http://www.directfb.org/ has been broken for more than
five months and suggests using http://elinux.org/DirectFB instead.

Signed-off-by: Jonathan Ben-Avraham <yba@tkos.co.il>
Signed-off-by: Peter Korsgaard <peter@korsgaard.com>

package/directfb/Config.in

@@ -8,7 +8,13 @@ config BR2_PACKAGE_DIRECTFB
 	select BR2_PACKAGE_FREETYPE
 	select BR2_PACKAGE_ZLIB
 	help
-	  http://www.directfb.org/
+	  DirectFB (Direct Frame Buffer) is a set of graphics APIs implemented
+	  on top of the Linux Frame Buffer (fbdev) abstraction layer. It is an
+	  alternative to X11 with a smaller memory footprint that still has an
+	  integrated windowing system. As of 4 October 2015, DirectFB's website
+	  http://www.directfb.org/ is down. See alternative site listed below.
+
+	  http://elinux.org/DirectFB
 
 if BR2_PACKAGE_DIRECTFB