Merge pull request #92 from contentstack/dx-7335-deprecation-msg

docs: add deprecation notice to README

Author: harshithad0703

README.md

@@ -1,3 +1,8 @@
+> [!WARNING]
+> **This repo is deprecated and no longer maintained. Security updates are not supported. We recommend avoiding its use.**
+>
+> For new projects, use [Contentstack Kickstarts](https://www.contentstack.com/docs/developers/kickstarts).
+
 [![Contentstack Logo](/public/contentstack.png)](https://www.contentstack.com/)
 
 # Build a Starter Website with React.js and Contentstack