Fixed #23430 -- simplified gunicorn deployment docs.

When Gunicorn is installed, a ``gunicorn`` command is available which starts

the Gunicorn server process. At its simplest, gunicorn just needs to be called

with the location of a WSGI application object.::

with the location of a file containing a WSGI application object named

`application`. So for a typical Django project, invoking gunicorn would look

like::

    gunicorn [OPTIONS] APP_MODULE

    gunicorn myproject.wsgi

Where ``APP_MODULE`` is of the pattern ``MODULE_NAME:VARIABLE_NAME``. The

module name should be a full dotted path. The variable name refers to a WSGI

callable that should be found in the specified module.

So for a typical Django project, invoking gunicorn would look like::

    gunicorn myproject.wsgi:application

(This requires that your project be on the Python path; the simplest way to

ensure that is to run this command from the same directory as your

``manage.py`` file.)

This will start one process running one thread listening on ``127.0.0.1:8000``.

It requires that your project be on the Python path; the simplest way to ensure

that is to run this command from the same directory as your ``manage.py`` file.

See Gunicorn's `deployment documentation`_ for additional tips.