Runs the beamlet command line from Mix, in development.
$ mix beamlet setup
$ mix beamlet tokens.create laptop
$ mix beamlet --help
It works on the data dir your project's config names, whether or not the beamlet is running. It exits non-zero when a command fails, so it works in scripts.
Beamlet.CLI describes each command. A release has no Mix, so the
standalone server ships bin/beamlet instead, and your own release
can call Beamlet.CLI.main/1 from its eval command the same way.