[TASK] Use of siteLanguage(“locale”) corrected

Releases: main, 13.4, 12.4

Author: brosua

Documentation/Conditions/Index.rst

@@ -1275,7 +1275,13 @@ siteLanguage()
         Returns the language ID as an integer.
 
     :typoscript:`siteLanguage("locale")`
-        Returns the current locale as a string, for example `en-GB` or `de-DE`.
+        Returns the current locale as `\TYPO3\CMS\Core\Localization\Locale`.
+        You can call all public methods of the object, for example
+        :typoscript:`siteLanguage("locale").getName()` returns `en-GB` or `de-DE`.
+
+        **Note**: In version 12 there was an unintentional breaking change,
+        whereby an object and not a string is returned.
+        A future TYPO3 release may address implementing a shortcut for this.
 
     :typoscript:`siteLanguage("base")`
         Returns the configured base URL as a string.