[TASK] Clarify changelog file placement

Releases: master
Resolves: #85039
Change-Id: I2e995aef69edd099d49b5915ab61c38e7d0af49e
Reviewed-on: https://review.typo3.org/56999


Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: TYPO3com <no-reply@typo3.com>
Reviewed-by: Tymoteusz Motylewski <t.motylewski@gmail.com>
Tested-by: Tymoteusz Motylewski <t.motylewski@gmail.com>