[DOCS] Correct information about slug postModifiers

The key `record` might not always contain the full record. When using the
`FormSlugAjaxController`, the record might just contain a sub-set of
fields.

Resolves: #94388
Releases: main, 12.4, 11.5
Change-Id: Ie72d6701ebef4da8af8b039e0da056e28b8d0ecb
Reviewed-on: https://review.typo3.org/c/Packages/TYPO3.CMS/+/84691


Tested-by: Christian Kuhn <lolli@schwarzbu.ch>
Reviewed-by: Christian Kuhn <lolli@schwarzbu.ch>
Tested-by: core-ci <typo3@b13.com>

typo3/sysext/core/Documentation/Changelog/9.5.x/Feature-88198-TCA-basedSlugModifiersForExtensions.rst

@@ -36,7 +36,7 @@ The method then receives a parameter array with the following values:
         'slug' ... the slug to be used
         'workspaceId' ... the workspace ID, "0" if in live workspace
         'configuration' ... the configuration of the TCA field
-        'record' ... the full record to be used
+        'record' ... important fields of the record (available fields might differ from usage type)
         'pid' ... the resolved parent page ID
         'prefix' ... the prefix that was added
         'tableName' ... the table of the slug field