Remove irrelevant reference from "Tying it all together"

Sorry Jon, but this might not be of any help to new Git users ;)

Acked-by: Jon Loeliger <jdl@jdl.com>
Signed-off-by: Thomas Ackermann <th.acker@arcor.de>
Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/user-manual.txt b/Documentation/user-manual.txt
index b3ed849..b7c7256 100644
--- a/Documentation/user-manual.txt
+++ b/Documentation/user-manual.txt
@@ -3924,8 +3924,7 @@
 result to the file pointed at by `.git/HEAD`, so that we can always see
 what the last committed state was.
 
-Here is an ASCII art by Jon Loeliger that illustrates how
-various pieces fit together.
+Here is a picture that illustrates how various pieces fit together:
 
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