bpo-37149: Change Shipman tkinter link from archive.org to TkDocs (GH-22188)


The new link responds much faster and begins with a short explanation of the status of the doc.
(cherry picked from commit 06d0b8b67e8aebd8fe4c34e97d6915c11f4afa30)

Co-authored-by: Mark Roseman <mark@markroseman.com>
diff --git a/Doc/library/tkinter.rst b/Doc/library/tkinter.rst
index 9f95425..7739f2f 100644
--- a/Doc/library/tkinter.rst
+++ b/Doc/library/tkinter.rst
@@ -31,7 +31,7 @@
    `TKDocs <http://www.tkdocs.com/>`_
       Extensive tutorial plus friendlier widget pages for some of the widgets.
 
-   `Tkinter 8.5 reference: a GUI for Python <https://web.archive.org/web/20190524140835/https://infohost.nmt.edu/tcc/help/pubs/tkinter/web/index.html>`_
+   `Tkinter 8.5 reference: a GUI for Python <https://www.tkdocs.com/shipman/>`_
       On-line reference material.
 
    `Tkinter docs from effbot <http://effbot.org/tkinterbook/>`_