doc/git-log: describe --diff-merges=off

Signed-off-by: Sergey Organov <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: sorganov

Documentation/git-log.txt

@@ -145,14 +145,18 @@ combined-diff option or with `--no-diff-merges`).
 	rename or copy detection have been requested).
 
 -m::
---diff-merges::
 	This flag makes the merge commits show the full diff like
 	regular commits; for each merge parent, a separate log entry
 	and diff is generated. An exception is that only diff against
 	the first parent is shown when `--first-parent` option is given;
 	in that case, the output represents the changes the merge
 	brought _into_ the then-current branch.
 
+--diff-merges=off::
+--no-diff-merges::
+	Disable output of diffs for merge commits (default). Useful to
+	override `-m`, `-c`, or `--cc`.
+
 :git-log: 1
 include::diff-options.txt[]