Document that the default metadata version can be overridden in config file.

From: Goswin Brederlow <brederlo@informatik.uni-tuebingen.de>

This is already mentioned in the config documentation, but not in the
place when the normal default is mentioned.

Fixes-debian-bug: 396914

ChangeLog

@@ -1,6 +1,7 @@
 Changes Prior to 2.5.6 release
     -   Fix bug which meant "bitmap=xxx" in mdadm.conf was not handled
 	properly.
+    -	Documentation updates.
 
 Changes Prior to 2.5.5 release
     -   Don't #include linux/blkpg.h as that isn't safe.  Just

mdadm.8

@@ -273,6 +273,12 @@ says to get a list of array devices from
 .B -e ", " --metadata=
 Declare the style of superblock (raid metadata) to be used.  The
 default is 0.90 for --create, and to guess for other operations.
+The default can be overridden by setting the
+.B metadata
+value for the
+.B CREATE
+keyword in
+.BR mdadm.conf .
 
 Options are:
 .RS