Merge pull request #9654 from nextcloud/backport/9646/stable25

[stable25] Typo in class loader `PSR-4` instead of `PSR-0`

Author: ChristophWurst

developer_manual/digging_deeper/classloader.rst

@@ -10,7 +10,7 @@ The classloader is provided by Nextcloud and loads all your classes automaticall
 PSR-4 autoloading
 -----------------
 
-Nextcloud uses a  :ref:`PSR-0 autoloader<psr4>`. The namespace **\\OCA\\MyApp**
+Nextcloud uses a  :ref:`PSR-4 autoloader<psr4>`. The namespace **\\OCA\\MyApp**
 is mapped to :file:`/apps/myapp/lib/`. Afterwards normal PSR-4 rules apply, so
 a folder is a namespace section in the same casing and the class name matches
 the file name.