Add --help to cli

[NoahTheDuke]

Hey liquidz, love antq. I forget exactly how to use it when it's been a little while, and then I have to load up the readme because there's no --help CLI flag to print usage/flags. It would be nice to have a description of usage when given --help to remind us of the options.

$ clojure -M:antq --help
Unknown option: "--help"