Update README.md o7

Author: OliverSchlueter

README.md

@@ -16,6 +16,15 @@
 
 Simple, lightweight and feature-rich NPC plugin for **[Paper](https://papermc.io/software/paper)** (and **[Folia](https://papermc.io/software/folia)**) servers using packets.
 
+> [!CAUTION]
+> This repository is no longer maintained and has been merged into our new monorepo: [https://github.com/FancyMcPlugins/fancyplugins](https://github.com/FancyMcPlugins/fancyplugins).
+>
+> For the latest updates, issues, and contributions, please visit the monorepo. This repo remains available for historical reference but will no longer receive updates.
+> 
+> Please do not create issues or pull requests here, as they will not be addressed. (The currently open issues will be migrated to the new repository.)
+>
+> Read [this blog article](https://docs.fancyplugins.de/blog/why-monorepo/) to learn more about the reasons, why we switched to a monorepo.
+
 </div>
 
 ## Features