git-checkout.txt: fix one syntax line

pclouds · gitster · commit 37f80025cdc5 · 2019-04-02T13:56:58.000+09:00
&lt;branch&gt; can be omitted in this syntax, and it's actually documented a
few paragraphs down:

  You could omit &lt;branch&gt;, in which case the command degenerates to
  "check out the current branch", which is a glorified no-op with
  rather expensive side-effects to show only the tracking information,
  if exists, for the current branch.

Signed-off-by: Nguyễn Thái Ngọc Duy &lt;pclouds@gmail.com&gt;
Signed-off-by: Junio C Hamano &lt;gitster@pobox.com&gt;
diff --git a/Documentation/git-checkout.txt b/Documentation/git-checkout.txt
@@ -23,7 +23,7 @@ or the specified tree.  If no paths are given, 'git checkout' will
 also update `HEAD` to set the specified branch as the current
 branch.
 
-'git checkout' <branch>::
+'git checkout' [<branch>]::
 	To prepare for working on <branch>, switch to it by updating
 	the index and the files in the working tree, and by pointing
 	HEAD at the branch. Local modifications to the files in the
