docs: imaplib: idle: versionadded:: next

Author: Forest

Doc/library/imaplib.rst

@@ -385,6 +385,8 @@ An :class:`IMAP4` instance has the following methods:
       iteration, and public method to remain stable, but should not subclass,
       instantiate, compare, or otherwise directly reference the class.
 
+   .. versionadded:: next
+
 
 .. method:: IMAP4.list([directory[, pattern]])