[TASK] Improve formatting in docblocks of LanguageService class

The docblocks in the LanguageService class are used for an automatically
generated API documentation in TYPO3 Explained. The formatting of some
code blocks can be improved.

Resolves: #99528
Related: https://github.com/TYPO3-Documentation/TYPO3CMS-Reference-CoreApi/pull/2590
Releases: main
Change-Id: Idfb29d45f6c452e7f2a51ef81df63378b4e0b247
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/77367


Reviewed-by: Georg Ringer <georg.ringer@gmail.com>
Reviewed-by: Lina Wolf <112@linawolf.de>
Tested-by: core-ci <typo3@b13.com>
Tested-by: Lina Wolf <112@linawolf.de>
Tested-by: Georg Ringer <georg.ringer@gmail.com>