[PATCH] Document "commit --only".

The documentation was there earlier, but removed by
4170a19587280eeb3663a47a6fd993910de78076.

That option being the default now, it could perhaps be actually
removed, but since it is there, and mentionned in the SYNOPSIS, it
should be actually documented.

Signed-off-by: Matthieu Moy <redacted>
---
 Documentation/git-commit.txt |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index d024c03..0bdf794 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt

@@ -116,6 +116,11 @@ but can be used to amend a merge commit.
 	as well.  This is usually not what you want unless you
 	are concluding a conflicted merge.
 
+-o|--only::
+	Commit only the files specified on the command line.
+	This format cannot be used during a merge. This is the
+	default.
+
 -q|--quiet::
 	Suppress commit summary message.
 

-- 
1.5.1.3