Add logging.config.BaseConfigurator.config (#14590)

stdlib/logging/config.pyi

@@ -106,7 +106,7 @@ class ConvertingTuple(tuple[Any, ...], ConvertingMixin):  # undocumented
     @overload
     def __getitem__(self, key: slice) -> Any: ...
 
-class BaseConfigurator:  # undocumented
+class BaseConfigurator:
     CONVERT_PATTERN: Pattern[str]
     WORD_PATTERN: Pattern[str]
     DOT_PATTERN: Pattern[str]
@@ -115,6 +115,8 @@ class BaseConfigurator:  # undocumented
     value_converters: dict[str, str]
     importer: Callable[..., Any]
 
+    config: dict[str, Any]  # undocumented
+
     def __init__(self, config: _DictConfigArgs | dict[str, Any]) -> None: ...
     def resolve(self, s: str) -> Any: ...
     def ext_convert(self, value: str) -> Any: ...