Fix wrong indentation of a paragraph in documentation (GH-12868)

This paragraph doesn't seem to be a part of code, but merged into previous code block.
(cherry picked from commit 9941f96)

Co-authored-by: cocoatomo <cocoatomo77@gmail.com>

Author: miss-islington

Doc/library/typing.rst

@@ -956,8 +956,8 @@ The module defines the following classes, functions and decorators:
 
       def fetch_response() -> Response: ...
 
-    Note that returning instances of private classes is not recommended.
-    It is usually preferable to make such classes public.
+   Note that returning instances of private classes is not recommended.
+   It is usually preferable to make such classes public.
 
 .. data:: Any