Update README to reflect project archiving

Added note about project archiving and integration.

Author: repolevedavaj

README.md

@@ -3,6 +3,8 @@
 ![Build](https://github.com/Project-Env/project-env-shell/workflows/Build/badge.svg)
 [![Quality Gate Status](https://sonarcloud.io/api/project_badges/measure?project=Project-Env_project-env-shell&metric=alert_status)](https://sonarcloud.io/dashboard?id=Project-Env_project-env-shell)
 
+**Note that this project has been archived, as the shell integration has been integrated into [project-env-cli](https://github.com/Project-Env/project-env-cli).**
+
 The Project-Env Shell integration application allows to use tools setup by the Project-Env CLI in a shell environment. See [Project-Env](https://project-env.github.io/) for more details.
 
 ## Installation