Correct splitext() description, and example (#74377)

`splitext()` returns a 2-tuple of strings, and the last element of the return value includes the `.`

docs/docsite/rst/user_guide/playbooks_filters.rst

@@ -1622,12 +1622,12 @@ To get the root and extension of a path or file name (new in version 2.0)::
     # with path == 'nginx.conf' the return would be ('nginx', '.conf')
     {{ path | splitext }}
 
-The ``splitext`` filter returns a string. The individual components can be accessed by using the ``first`` and ``last`` filters::
+The ``splitext`` filter always returns a pair of strings. The individual components can be accessed by using the ``first`` and ``last`` filters::
 
     # with path == 'nginx.conf' the return would be 'nginx'
     {{ path | splitext | first }}
 
-    # with path == 'nginx.conf' the return would be 'conf'
+    # with path == 'nginx.conf' the return would be '.conf'
     {{ path | splitext | last }}
 
 To join one or more path components::