Documentation: rerere is enabled by default these days.

Signed-off-by: NJunio C Hamano <gitster@pobox.com>

Documentation/config.txt

@@ -507,7 +507,9 @@ gc.rerereunresolved::
 rerere.enabled::
 	Activate recording of resolved conflicts, so that identical
 	conflict hunks can be resolved automatically, should they
-	be encountered again.  See gitlink:git-rerere[1].
+	be encountered again.  gitlink:git-rerere[1] command is by
+	default enabled, but can be disabled by setting this option to
+	false.
 
 gitcvs.enabled::
 	Whether the CVS server interface is enabled for this repository.

Documentation/git-rerere.txt

@@ -22,10 +22,6 @@ automerge results and corresponding hand-resolve results on the
 initial manual merge, and later by noticing the same automerge
 results and applying the previously recorded hand resolution.
 
-[NOTE]
-You need to set the config variable rerere.enabled to enable this
-command.
-
 
 COMMANDS
 --------