Update docs for change of default merge backend

Make it clear that `ort` is the default merge strategy now rather than
`recursive`, including moving `ort` to the front of the list of merge
strategies.

Signed-off-by: Elijah Newren <newren@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/merge-options.txt b/Documentation/merge-options.txt
index f819bd8..72b5318 100644
--- a/Documentation/merge-options.txt
+++ b/Documentation/merge-options.txt
@@ -112,7 +112,7 @@
 	Use the given merge strategy; can be supplied more than
 	once to specify them in the order they should be tried.
 	If there is no `-s` option, a built-in list of strategies
-	is used instead (`recursive` when merging a single head,
+	is used instead (`ort` when merging a single head,
 	`octopus` otherwise).
 
 -X <option>::