[PATCH] Documentation/git-commit: reword the --amend explanation

["Carlos Martín Nieto" <cmn@elego.de>]

The explanation for 'git commit --amend' talks about preparing a tree
object, which shouldn't be how user-facing documentation talks about
commit.

Reword it to say it works as usual, but replaces the current commit.
---

The current text is from 2006, which I guess explains the wording.

 Documentation/git-commit.txt | 13 +++++--------
 1 file changed, 5 insertions(+), 8 deletions(-)

diff --git a/Documentation/git-commit.txt b/Documentation/git-commit.txt
index 42c22bb..48dac29 100644
--- a/Documentation/git-commit.txt
+++ b/Documentation/git-commit.txt
@@ -198,14 +198,11 @@ OPTIONS
 	without changing its commit message.
 
 --amend::
-	Used to amend the tip of the current branch. Prepare the tree
-	object you would want to replace the latest commit as usual
-	(this includes the usual -i/-o and explicit paths), and the
-	commit log editor is seeded with the commit message from the
-	tip of the current branch. The commit you create replaces the
-	current tip -- if it was a merge, it will have the parents of
-	the current tip as parents -- so the current top commit is
-	discarded.
+	Amend the tip of the current branch. The commit is prepared as
+	usual (including -i/-o and explicit paths) and the editor
+	starts off with the current tip's commit message. The new
+	commit has the same parents and author as the current one and
+	replaces it as the tip.
 +
 --
 It is a rough equivalent for:
-- 
1.8.2.524.g8f8def7