Add deprecation notice

Ole Markus With · Ole Markus With · commit 5e0c59a1ebe1 · 2020-10-07T23:15:43.000+02:00
diff --git a/addons/metrics-server/README.md b/addons/metrics-server/README.md
@@ -1,5 +1,7 @@
 # Kubernetes Metrics Server
 
+**This addon is deprecated. Set `spec.metricsServer.enabled: true` instead**
+
 ## User guide
 
 You can find the user guide in
