Update README.md

Author: zavgorodnii

README.md

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 # Neutron Cosmwasm SDK
 
-This repository contains the source code of Neutron Cosmwasm SDK for interacting with [Neutron blockchain](https://github.com/neutron-org/neutron)
+## ⚠️ Project Status: Archived & Maintenance Mode
+
+The neutron repository has been officially archived and placed into long-term maintenance mode. 
+
+* **Security Updates**: The development team is no longer actively monitoring this codebase or tracking security vulnerabilities. 
+* **Future Development**: The community is highly encouraged to fork this repository to implement custom improvements, bug fixes, or continued development.
+
+Thank you to everyone who contributed to the project!
 
 ## Overview
 
+This repository contains the source code of Neutron Cosmwasm SDK for interacting with [Neutron blockchain](https://github.com/neutron-org/neutron)
+
 ### Neutron SDK
 
 The Neutron SDK is contained inside `packages` folder and consists of the following subpackages: