use tools.cli for command-line arguments feature

[rplevy-draker]

If no cli-options are provided, the arguments are parsed as is, but if options are provided they are used.

Without options:

  {:src args, :as :cli}

With options:

  {:src args, :as :cli, :cli-options ["-f" "--foo.bar" :parse-fn #(Integer. %)]}

Another option to provide a function to do something with usage:

  {:src args :as :cli, :cli-help-fn (fn [help-key banner] (when (= help-key :help) (println banner) (System/exit 0)))}