(docs): note on minikube profile setting

Author: kameshsampath

documentation/modules/ROOT/pages/setup.adoc

@@ -105,16 +105,19 @@ Before installing Knative and its components, we need to add few startup config
 
 [source,bash,subs="+macros,+attributes"]
 ----
-minikube start -p knative --memory=8192 --cpus=4 \#<1> 
-  --kubernetes-version=v1.12.0 \#<2> 
-  --vm-driver=hyperkit \#<3>  
+minikube profile knative \#<1>
+
+minikube start -p knative --memory=8192 --cpus=4 \#<2> 
+  --kubernetes-version=v1.12.0 \#<3> 
+  --vm-driver=hyperkit \#<4>  
   --disk-size=50g \
   --extra-config=apiserver.enable-admission-plugins="LimitRanger,NamespaceExists,NamespaceLifecycle,ResourceQuota,ServiceAccount,DefaultStorageClass,MutatingAdmissionWebhook"
 ----
 
-<1> Starting a profile named **knative**
-<2> Minimum kubernetes version needs to be >= 1.12.0, refer to issue https://github.com/knative/serving/issues/3067 for more details.
-<3> If you are on linux then use `--vm-driver=kvm2`
+<1> Setting minikube profile to **knative** so that all future minikube commands are executed with this profile context
+<2> Starting a profile named **knative**
+<3> Minimum kubernetes version needs to be >= 1.12.0, refer to issue https://github.com/knative/serving/issues/3067 for more details.
+<4> If you are on linux then use `--vm-driver=kvm2`
 
 [#install-knative-istio]
 ==== Install Istio