add matching text to readme

README.md

@@ -1,3 +1,10 @@
+Our new lesson infrastructure, [The Carpentries Workbench](https://carpentries.github.io/workbench/)
+became the default for official Carpentries lessons in May 2023.
+
+The Workbench is designed to be more accessible and easier to use than the styles
+infrastructure by separating tools from the content. As such, **using this repository for
+lessons is no longer supported by The Carpentries Core Team**.
+
 [![Website Check Status](https://github.com/carpentries/lesson-example/workflows/Website/badge.svg)](https://github.com/carpentries/lesson-example/actions/workflows/website.yml?query=workflow%3AWebsite)
 
 lesson-example