Help message rather than showing the status by default

[marioortizmanero]

Currently, there is no --help parameter. This would come in handy for new users, and should also point to this repository.

This would mean that whenever an argument isn't found, rather than calling output, the help message would be shown. Current behaviour:

case "$1" in
    --up)
        volUp
        ;;

    # Other arguments

    *)
        # By default print output for bar.
        output
        ;;
esac