Now it prints help like that:
Usage:
To install a new Lisp implementaion:
ros install impl [options]
or a system from the GitHub:
ros install fukamachi/prove/v2.0.0 [repository... ]
or an asdf system from quicklisp:
ros install quicklisp-system [system... ]
or a local script:
ros install ./some/path/to/script.ros [path... ]
or a local system:
ros install ./some/path/to/system.asd [path... ]
...