Update README.md

README.md

@@ -3,6 +3,14 @@
 Gaffer Doc
 ==========
 
+## This project has been archived
+
+**This project has been archived and is no longer under active maintenance. Should you have any questions or require further information, please do not hesitate to reach out to us at the following email address.**
+
+**oss@gchq.gov.uk**
+
+---
+
 This repository contains all the documentation for Gaffer, which is published [here](https://gchq.github.io/gaffer-doc/).
 
 # Building the documentation
@@ -35,4 +43,4 @@ Docs can be build and served locally (on `localhost:8000`) by using:
 mkdocs serve
 ```
 
-This automatically updates and refreshes when local changes are made. Although it might take a few seconds due to the amount of content.
+This automatically updates and refreshes when local changes are made. Although it might take a few seconds due to the amount of content.