[DOCS] Add changelog folder for v12.2

Resolves: #99293
Releases: main
Change-Id: I64fd454f3c8e24389aeda8312e1a68398afb4d02
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/76941


Reviewed-by: Benni Mack <benni@typo3.org>
Reviewed-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: Stefan Bürk <stefan@buerk.tech>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Benni Mack <benni@typo3.org>