Tools for wrapping build tasks in CLIs.

Like `cli-matic`, this provides a higher-level wrapper over
`clojure.tools.cli`. However, `trident.cli` is designed specifically for
making build tasks easily reusable (including tasks not defined using
`trident.cli`).

See [[_cli_format]] for general usage.
Most of the time, the only thing you'll need from this namespace is
[[defmain]]. See the [[trident.build]] source for some non-contrived example
usage.