[BUGFIX] Mention new TypoScriptService namespace

This explains where `TypoScriptService` was moved to.

In order to ease the migration the documentation now
mentions the full class name.

Releases: master, 9.5, 8.7
Resolves: #88868
Change-Id: Id83c83e3932fdea6a29127c1de6bee9320fa9110
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/61396


Tested-by: TYPO3com <noreply@typo3.com>
Tested-by: Björn Jacob <bjoern.jacob@tritum.de>
Tested-by: Jörg Bösche <typo3@joergboesche.de>
Tested-by: Anja Leichsenring <aleichsenring@ab-softlab.de>
Reviewed-by: Björn Jacob <bjoern.jacob@tritum.de>
Reviewed-by: Jörg Bösche <typo3@joergboesche.de>
Reviewed-by: Anja Leichsenring <aleichsenring@ab-softlab.de>

typo3/sysext/core/Documentation/Changelog/8.7/Important-78650-TypoScriptServiceClassMovedFromExtbaseToCore.rst

@@ -12,7 +12,8 @@ Description
 The PHP class :php:`TypoScriptService` has been moved to the core extension, as it has no direct link
 to Extbase, and a lot of other system extensions are using the class.
 
-The old class name is still registered as a class alias, so extensions can call the class via
-the Extbase PHP namespace in TYPO3 v8 without any downsides.
+The old class name :php:`TYPO3\CMS\Extbase\Service\TypoScriptService` is registered as a class alias
+for the new class name :php:`TYPO3\CMS\Core\TypoScript\TypoScriptService`, so extensions can call the
+class via the Extbase PHP namespace in TYPO3 v8 without any downsides.
 
 .. index:: PHP-API, ext:extbase, TypoScript