diff: document --no-color-moved

Add documentation for --no-color-moved.

Signed-off-by: Phillip Wood <phillip.wood@dunelm.org.uk>
Reviewed-by: Stefan Beller <sbeller@google.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/diff-options.txt b/Documentation/diff-options.txt
index 0378cd5..151690f 100644
--- a/Documentation/diff-options.txt
+++ b/Documentation/diff-options.txt
@@ -293,6 +293,10 @@
 	`dimmed_zebra` is a deprecated synonym.
 --
 
+--no-color-moved::
+	Turn off move detection. This can be used to override configuration
+	settings. It is the same as `--color-moved=no`.
+
 --color-moved-ws=<modes>::
 	This configures how white spaces are ignored when performing the
 	move detection for `--color-moved`.