Support zsh completion for subcommand of ws

[rikuson]

• https://gist.github.com/mitukiii/4954559
• https://github.com/ohmyzsh/ohmyzsh/blob/master/plugins/pass/_pass
• https://rcmdnk.com/blog/2015/05/15/computer-linux-mac-zsh/
• https://masawada.hatenablog.jp/entry/2021/10/08/103000