Merge pull request spring-projects#21650 from fastso

* pr/21650:
  Polish 'Clarify documentation for probe ports'
  Clarify documentation for probe ports

Closes spring-projectsgh-21650

spring-boot-project/spring-boot-docs/src/docs/asciidoc/production-ready-features.adoc

@@ -894,18 +894,21 @@ You can then configure your Kubernetes infrastructure with the following endpoin
 livenessProbe:
   httpGet:
     path: /actuator/health/liveness
-    port: liveness-port
+    port: <actuator-port>
   failureThreshold: ...
   periodSeconds: ...
 
 readinessProbe:
   httpGet:
     path: /actuator/health/readiness
-    port: liveness-port
+    port: <actuator-port>
   failureThreshold: ...
   periodSeconds: ...
 ----
 
+NOTE: `<actuator-port>` should be set to the port that the actuator endpoints are available on.
+It could be the main web server port, or a separate management port if the `"management.server.port"` property has been set.
+
 These health groups are only enabled automatically if the application is <<deployment.adoc#cloud-deployment-kubernetes,running in a Kubernetes environment>>.
 You can enable them in any environment using the configprop:management.health.probes.enabled[] configuration property.