branch doc: update description for `--list`

The paragraph begins with a sample command line `git branch <name>`
that has nothing to do with the option being described.  Remove it,
but use the space to instead show that multiple patterns can be
given.

Also mention the unfortunate `-l` that can be easily confused with
it.

Signed-off-by: Junio C Hamano <gitster@pobox.com>
Reviewed-by: Jonathan Nieder <jrnieder@gmail.com>
Reviewed-by: Ævar Arnfjörð Bjarmason <avarab@gmail.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

Documentation/git-branch.txt

@@ -142,8 +142,13 @@ This option is only applicable in non-verbose mode.
 	List both remote-tracking branches and local branches.
 
 --list::
-	Activate the list mode. `git branch <branchname>` would try to create a branch,
-	use `git branch --list <pattern>` to list matching branches.
+	List branches.  With optional `<pattern>...`, e.g. `git
+	branch --list 'maint-*'`, list only the branches that match
+	the pattern(s).
++
+This should not be confused with `git branch -l <branchname>`,
+which creates a branch named `<branchname>` with a reflog.
+See `--create-reflog` above for details.
 
 -v::
 -vv::