Merge pull request #44755 from mhrivnak/fix-rhv-machineset-yaml

fixes invalid YAML example by changing capitalization

Author: apinnick

modules/machineset-yaml-rhv.adoc

@@ -23,7 +23,7 @@ metadata:
   namespace: openshift-machine-api
 spec:
   replicas: <number_of_replicas> <4>
-  Selector: <5>
+  selector: <5>
     matchLabels:
       machine.openshift.io/cluster-api-cluster: <infrastructure_id> <1>
       machine.openshift.io/cluster-api-machineset: <infrastructure_id>-<role> <3>