Add archive warning (#28)

README.md

diff --git a/README.md b/README.md
index 9602438..3681670 100644
--- a/README.md
+++ b/README.md
@@ -1 +1,5 @@
+> [!WARNING]
+> This repo has been archived. All files have been moved to [apache/cloudberry - devops](https://github.com/apache/cloudberry/tree/main/devops).
+> Please submit feedback or improvements in the new repository.
+
 # DevOps and Release for Apache Cloudberry (Incubating)