docs: fix wait-for-service example and note about merging existing re…

…sources

docs/modules/ROOT/pages/index.adoc

@@ -685,7 +685,7 @@ The service name strongly depends on the Helm dependency to be installed, so you
 
 This configuration will add the following init-containers in the Deployment resource of your Quarkus application:
 
-`src/main/helm/kubernetes/templates/deployment.yaml`:
+`target/helm/kubernetes/<chart name>/templates/deployment.yaml`:
 [source,yaml]
 ----
 initContainers:
@@ -778,6 +778,8 @@ quarkus.helm.expressions.0.path=(kind == Service && metadata.name == quarkus-hel
 quarkus.helm.expressions.0.expression={{- template "mychart.labels" }}
 ----
 
+Note that the content of these resources at `src/main/helm/templates/<kind>.yaml` will only be added at the beginning of the generated resource at `target/helm/kubernetes/<chart name>/templates/<kind>.yaml`, by no means, it will be merged. If you want to merge existing Kubernetes/OpenShift resources to the autogenerated ones, you need to follow https://quarkus.io/guides/deploying-to-kubernetes#using-existing-resources[this guide] which does not support Helm expressions.
+
 [[push-to-helm-repositories]]
 == Push to Helm Repositories