Add missing instruction on adding the CA configmap

Signed-off-by: Roy Golan <[email protected]>

serverlessworkflow/modules/ROOT/pages/cloud/operator/add-custom-ca-to-a-workflow-pod.adoc

@@ -136,6 +136,17 @@ spec:
 
 Similar to a deployment spec, a serverless workflow has a spec.podTemplate, with minor differences, but the change is almost identical.
 In this case, we are mounting some ingress ca-bundle because we want our workflow to reach the `.apps.my-cluster-name.my-cluster-domain` SSL endpoint.
+
+In this example we pull the ingress CA of OpenShift's ingress deployment because this
+is the CA that is used to sign certificates for routes. It can be any CA that is signing the target service certificate.
+Here's how to copy the ingress ca cert to the desired namespace:
+
+[source,shell]
+---
+kubectl config set-context --current --namespace=my-namespace
+kubectl get cm -n openshift-config-managed default-ingress-cert  -o yaml | awk '!/namespace:.*$/' | sed 's/default-ingress-cert/ingress-ca/'  | kubectl create -f -
+---
+
 Here is the relevant spec section of a workflow with the changes:
 
 [source,yaml]