bpo-42153 Fix link to IMAP documents in imaplib.rst (GH-23297)

The University of Washington stopped hosting the IMAP documents. Link to a rescued copy on GitHub.

Author: Pixmew

Doc/library/imaplib.rst

@@ -174,9 +174,9 @@ example of usage.
 
 .. seealso::
 
- Documents describing the protocol, and sources and binaries  for servers
- implementing it, can all be found at the University of Washington's *IMAP
- Information Center* (https://www.washington.edu/imap/).
+ Documents describing the protocol, sources for servers
+ implementing it, by the University of Washington's IMAP Information Center
+ can all be found at (**Source Code**) https://github.com/uw-imap/imap (**Not Maintained**).
 
 
 .. _imap4-objects:

Misc/NEWS.d/next/Documentation/2020-11-15-13-46-31.bpo-42153.KjBhx3.rst

@@ -0,0 +1 @@
+Fix the URL for the IMAP protocol documents.