chore: deprecation notice (#1)

README.md

@@ -1,5 +1,15 @@
+# DEPRECATED
+> [!WARNING]  
+> This repository is no longer supported as native Gnosis Chain support has been introduced in the upstream. Please use the [official documentation](https://docs.gnosischain.com/node/manual/beacon/nimbus).
+
+
+```shell
 docker build -t gnosischain/nimbus:latest --build-arg UPSTREAM_VERSION=v2.2.2 .
-docker push gnosischain/nimbus:latest   
+```
+
+```shell
+docker push gnosischain/nimbus:latest
+```
 
 # Starting the container in beacon mode 
 ```
@@ -10,4 +20,4 @@ docker push gnosischain/nimbus:latest
 # Starting the container in validator mode
 ```
 nimbus runs in both modes automatically 
-```
+```