git-worktree.txt: add missing -v to synopsis for worktree list

When verbose mode was added to `git worktree list` by 076b444
(worktree: teach `list` verbose mode, 2021-01-27), although the
documentation was updated to reflect the new functionality, the
synopsis was overlooked. Correct this minor oversight.

Signed-off-by: Eric Sunshine <[email protected]>
Signed-off-by: Junio C Hamano <[email protected]>

Author: sunshineco

Documentation/git-worktree.txt

@@ -10,7 +10,7 @@ SYNOPSIS
 --------
 [verse]
 'git worktree add' [-f] [--detach] [--checkout] [--lock [--reason <string>]] [-b <new-branch>] <path> [<commit-ish>]
-'git worktree list' [--porcelain]
+'git worktree list' [-v | --porcelain]
 'git worktree lock' [--reason <string>] <worktree>
 'git worktree move' <worktree> <new-path>
 'git worktree prune' [-n] [-v] [--expire <expire>]