Add a help menu for the subcommands

[rmarmorstein]

A help menu should be added for when you execute /ticket without any arguments, or with an incorrect subcommand.

This would increase usability a great deal. Thanks.

[ProjectInfinity]

If I missed anything it will be added.

[rmarmorstein]

Yeah, when i was figuring out the plugin, I had to refer to the Commands & Perms page on DBO and also redirect my staff there. When an invalid argument, or just /ticket is put in, it should give some kind of help :)

[ghost]

No error is returned either if you mistype a rerportrts command or use the wrong ticket sub command either, nothing happens.