added sentence to scaling worker nodes section

aldiazRH · aldiazRH · commit c944a8a73bec · 2022-07-22T09:10:43.000-04:00
diff --git a/modules/rosa-scaling-worker-nodes.adoc b/modules/rosa-scaling-worker-nodes.adoc
@@ -8,6 +8,8 @@
 
 If you have not enabled autoscaling for your machine pool, you can manually scale the number of compute (also known as worker) nodes in the pool to meet your deployment needs.
 
+You must scale each machine pool separately.
+
 .Prerequisites
 
 ifdef::openshift-rosa[]
