git-worktree.txt: keep subcommand listing in alphabetical order

This is probably not the best order. But it makes it no-brainer to know
where to insert new commands. At some point we might want to reorder at
least the synopsis part again, grouping commonly use subcommands together.

Signed-off-by: Nguyễn Thái Ngọc Duy <pclouds@gmail.com>
Reviewed-by: Eric Sunshine <sunshine@sunshineco.com>
Signed-off-by: Junio C Hamano <gitster@pobox.com>

builtin/worktree.c

@@ -13,8 +13,8 @@
 
 static const char * const worktree_usage[] = {
 	N_("git worktree add [<options>] <path> [<branch>]"),
-	N_("git worktree prune [<options>]"),
 	N_("git worktree list [<options>]"),
+	N_("git worktree prune [<options>]"),
 	NULL
 };