Deprecate Iris docs

Author: Ian Walls

content/en/docs/_index.md

@@ -7,7 +7,7 @@ weight: 10
 ---
 
 {{% alert title="VERSION" color="info"%}}
-This documentation supports the Iris version of FOLIO. Use the Releases menu to select another version as needed.
+This documentation supports the Iris version of the documentation, but is no longer being maintained. Use the Releases menu to select another version as needed.
 {{% /alert %}}
 
 Welcome to FOLIO documentation. FOLIO is an open source project that creates a new paradigm for collaboration between libraries, developers, and vendors.  This open platform moves the industry well beyond the traditional library management system, offering libraries more choices of features and services.