[TASK] Update documentation for scheduler options

Update the extension documentation to provide information about possible
options that can be provided while calling the scheduler script via
command line interface.

Resolves: #38506
Releases: master
Change-Id: I8372ec3ea83f8a18a05d0bb64e461341034fade0
Reviewed-on: http://review.typo3.org/43565


Reviewed-by: Philipp Gampe <philipp.gampe@typo3.org>
Tested-by: Philipp Gampe <philipp.gampe@typo3.org>
Reviewed-by: Andreas Fernandez <typo3@scripting-base.de>
Tested-by: Andreas Fernandez <typo3@scripting-base.de>