Update README.md

Author: OliverSchlueter

README.md

@@ -1,3 +1,11 @@
+> [!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 This repository is no longer maintained and has been merged into our new monorepo: [https://github.com/FancyMcPlugins/fancyplugins](https://github.com/FancyMcPlugins/fancyplugins).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 This repo remains available for historical reference but will no longer receive updates.
+>
+> Read [this blog article](https://docs.fancyplugins.de/blog/why-monorepo/) to learn more about the reasons, why we switched to a monorepo.
+
+
 # How to use
 
 ```kotlin
@@ -10,4 +18,4 @@ repositories {
 dependencies {
     implementation("de.oliver:FancyLib:<version>")
 }
-```
+```