Add blank line after note.

Author: giosiragusa

Doc/library/io.rst

@@ -65,6 +65,7 @@ In-memory text streams are also available as :class:`StringIO` objects::
    f = io.StringIO("some initial text data")
 
 .. note::
+
    When working with a non-blocking stream, be aware that operations on text I/O objects
    might raise a :exc:`BlockingIOError` if the stream cannot perform a read operation
    immediately.