[CLEANUP] Simplify registerPageTSConfigFile description

Resolves: #78886
Releases: master, 7.6
Change-Id: I1e5922ed510f0f43a6374f9dde061356290b72d9
Reviewed-on: https://review.typo3.org/50884


Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Robert van Kammen <rvkammen@hotmail.com>
Tested-by: Robert van Kammen <rvkammen@hotmail.com>
Reviewed-by: Wouter Wolters <typo3@wouterwolters.nl>
Tested-by: Wouter Wolters <typo3@wouterwolters.nl>