Startup probe is in beta since 1.18

Author: alex-slynko

content/en/docs/concepts/workloads/pods/pod-lifecycle.md

@@ -314,7 +314,7 @@ to stop.
 
 ### When should you use a startup probe?
 
-{{< feature-state for_k8s_version="v1.16" state="alpha" >}}
+{{< feature-state for_k8s_version="v1.18" state="beta" >}}
 
 Startup probes are useful for Pods that have containers that take a long time to
 come into service. Rather than set a long liveness interval, you can configure