[feature] shell completion

[Freed-Wu]

How about add shell completions for bash/zsh/fish/posh/etc? Thanks!

❯ progress -<TAB>
option
-a                       add additional command to default command list
--additional-command     add additional command to default command list
-c                       monitor only this command name (ex- firefox)
--command                monitor only this command name (ex- firefox)
--debug                  shows all warning/error messages
...