Documentation/git-pull.txt: Use more standard [NOTE] markup

Unlike other manual pages (e.g. git-blame.txt), this used *NOTE:*
to show a side note headed with boldface string "NOTE".  Use a paragraph
headed by [NOTE] like others instead.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
diff --git a/Documentation/git-pull.txt b/Documentation/git-pull.txt
index 5f55f64..d0f1595 100644
--- a/Documentation/git-pull.txt
+++ b/Documentation/git-pull.txt
@@ -38,7 +38,8 @@
 	for branch `<name>`, set configuration `branch.<name>.rebase`
 	to `true`.
 +
-*NOTE:* This is a potentially _dangerous_ mode of operation.
+[NOTE]
+This is a potentially _dangerous_ mode of operation.
 It rewrites history, which does not bode well when you
 published that history already.  Do *not* use this option
 unless you have read linkgit:git-rebase[1] carefully.