address review comments

docs/book/src/tasks/experimental-features/machineset-preflight-checks.md

@@ -2,6 +2,13 @@
 
 The `MachineSetPreflightChecks` feature can provide additional safety while creating new Machines and remediating existing unhealthy Machines of a MachineSet.
 
+When a MachineSet creates machines under certain circumstances, the operation fails or leads to a new machine that will be deleted and recreated in a short timeframe,
+leading to unwanted Machine churn. Some of these circumstances include, but not limited to, creating a new Machine when Kubernetes version skew could be violated or 
+joining a Machine when the Control Plane is upgrading leading to failure because of unclear kube-apiserver version. 
+
+Enabling `MachineSetPreflightChecks` provides safety in such circumstances by making sure that a Machine is only created when it is safe to do so.
+
+
 **Feature gate name**: `MachineSetPreflightChecks`
 
 **Variable name to enable/disable the feature gate**: `EXP_MACHINE_SET_PREFLIGHT_CHECKS`
@@ -10,33 +17,33 @@ The `MachineSetPreflightChecks` feature can provide additional safety while crea
 
 ### `ControlPlaneIsStable`
 
-* This preflight check ensures that the ControlPlane is currently stable i.e. the ControlPlane is currently not provisioning or not upgrading.   
+* This preflight check ensures that the ControlPlane is currently stable i.e. the ControlPlane is currently neither provisioning nor upgrading.   
 * This preflight check is only performed if:
   * The Cluster uses a ControlPlane provider.
-  * ControlPlane defines a version (`ControlPlane.Spec.Version` is defined).
+  * ControlPlane version is defined (`controlPlane.spec.version` is set).
 
 ### `KubernetesVersionSkew`
 
-* This preflight check ensures that the MachineSet and ControlPlane conform to the Kubernetes version skew.
+* This preflight check ensures that the MachineSet and the ControlPlane conform to the [Kubernetes version skew](https://kubernetes.io/releases/version-skew-policy/#kubelet).
 * This preflight check is only performed if:
     * The Cluster uses a ControlPlane provider.
-    * ControlPlane version is defined (`ControlPlane.Spec.Version` is set).
-    * MachineSet version is defined (`MachineSet.Spec.Template.Spec.Version` is set).
+    * ControlPlane version is defined (`controlPlane.spec.version` is set).
+    * MachineSet version is defined (`machineSet.spec.template.spec.version` is set).
 
 ### `KubeadmVersionSkew`
 
-* This preflight check ensures that the MachineSet and the ControlPlane conform the the kubeadm version skew.
+* This preflight check ensures that the MachineSet and the ControlPlane conform to the [kubeadm version skew](https://kubernetes.io/docs/setup/production-environment/tools/kubeadm/create-cluster-kubeadm/#kubeadm-s-skew-against-kubeadm).
 * This preflight check is only performed if:
-  * Cluster uses a ControlPlane provider.
-  * ControlPlane version is defined (`ControlPlane.Spec.Version` is set).
-  * MachineSet version is defined (`MachineSet.Spec.Template.Spec.Version` is set).
+  * The Cluster uses a ControlPlane provider.
+  * ControlPlane version is defined (`controlPlane.spec.version` is set).
+  * MachineSet version is defined (`machineSet.spec.template.spec.version` is set).
   * MachineSet uses the `Kubeadm` Bootstrap provider.
 
 
 ## Opting out of PreflightChecks
 
 Once the feature flag is enabled the preflight checks are enabled for all the MachineSets including new and existing MachineSets.
-It is possible to opt-out of one or all of the preflight checks on a per MachineSet basis by specifying a coma-separated list of the preflight checks on the 
+It is possible to opt-out of one or all of the preflight checks on a per MachineSet basis by specifying a comma-separated list of the preflight checks on the 
 `machineset.cluster.x-k8s.io/skip-preflight-checks` annotation on the MachineSet.  
 
 Examples: