add deprecation notice

README.md

 # docs.jami.net
 
+## DEPRECATED
+
+This repository and its static pages are deprecated in favour of
+https://git.jami.net/savoirfairelinux/jami-docs which uses Sphinx and
+is currently deployed to https://docs.jami.net.  The home page there
+links to the pages linked to in this repository's index.html file.
+
+## Old README
+
 This is a simple static page to group principal links used to document the [Jami](https://jami.net) project.
 
 ![](img/fullpage.png)