Update CLI usage.

.. code:: shell

   usage: mnpw [-h] [-v] [-V] [-d] [-t TIMEOUT]

               command [arguments [arguments ...]]

  usage: mnpw [-h] [-v] [-V] [-d] [-q] [-w] [-u] [-e] [-t TIMEOUT] command [arguments ...]

  My Nagios plugin wrapper.

    -v, --verbose         Verbose output

    -V, --version         show program's version number and exit

    -d, --dry-run         Dry-run, don't notify

    -q, --quiet, --silent

                          No output, except for errors.

    -w, --warn            Notify when the check status is WARNING.

    -u, --unknown         Notify when the check status is UNKNOWN.

    -e, --errors          Notify on check errors.

    -t TIMEOUT, --timeout TIMEOUT

                            Command timeout (in seconds), defaults to

                            10

                          Command timeout (in seconds), defaults to 10

Usage as library

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