[BUGFIX] Fix broken link in Documenting HowTo

Resolves: #90594
Releases: master, 9.5
Change-Id: I507863b071a75c8743a40c0502a1fc578ae29235
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/63499


Tested-by: Susanne Moog <look@susi.dev>
Tested-by: Oliver Bartsch <bo@cedev.de>
Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Daniel Goerz <daniel.goerz@posteo.de>
Reviewed-by: Susanne Moog <look@susi.dev>
Reviewed-by: Oliver Bartsch <bo@cedev.de>
Reviewed-by: Daniel Goerz <daniel.goerz@posteo.de>