Add automated worker machine management section to docs tasks

Author: enxebre

docs/book/src/SUMMARY.md

@@ -11,10 +11,12 @@
     - [Kubeadm based bootstrap](./tasks/kubeadm-bootstrap.md)
     - [Upgrading management and workload clusters](./tasks/upgrading-clusters.md)
     - [Upgrading Cluster API components](./tasks/upgrading-cluster-api-versions.md)
-    - [Configure a MachineHealthCheck](./tasks/healthcheck.md)
     - [Kubeadm based control plane management](./tasks/kubeadm-control-plane.md)
     - [Updating Machine Infrastructure and Bootstrap Templates](tasks/updating-machine-templates.md)
-    - [Using the Cluster Autoscaler](./tasks/cluster-autoscaler.md)
+    - [Automated worker Machine management](./tasks/automated-worker-machine-management/index.md)
+      - [Scaling](./tasks/automated-worker-machine-management/scaling.md)
+      - [Auto scaling](./tasks/automated-worker-machine-management/auto-scaling.md)
+      - [Health checking](./tasks/automated-worker-machine-management/healthchecking.md)
     - [Experimental Features](./tasks/experimental-features/experimental-features.md)
         - [MachinePools](./tasks/experimental-features/machine-pools.md)
         - [ClusterResourceSet](./tasks/experimental-features/cluster-resource-set.md)

docs/book/src/tasks/cluster-autoscaler.md renamed to docs/book/src/tasks/automated-worker-machine-management/auto-scaling.md

@@ -179,4 +179,4 @@ Before deploying a MachineHealthCheck, please familiarise yourself with the foll
 - If a Machine fails for any reason (if the FailureReason is set), the Machine will be remediated immediately
 
 <!-- links -->
-[management cluster]: ../reference/glossary.md#management-cluster
+[management cluster]: ../../reference/glossary.md#management-cluster

docs/book/src/tasks/healthcheck.md renamed to docs/book/src/tasks/automated-worker-machine-management/healthchecking.md

@@ -0,0 +1,3 @@
+# Automated worker Machine management
+
+This section details some tasks related to automated worker Machine management.

docs/book/src/tasks/automated-worker-machine-management/index.md

@@ -0,0 +1,13 @@
+# Scaling Nodes
+
+You can add or remove compute capacity for your cluster workloads by creating or removing Machines. A Machine express intent to have a Node with a defined form factor.
+
+Machines can be owned by scalable resources i.e. MachineSet and MachineDeployments.
+
+You can scale MachineSets and MachineDeployments in or out by expressing intent via .spec.replicas or updating the scale subresource e.g `kubectl scale machinedeployment foo --replicas=5`.
+
+When you delete a Machine directly or by scaling down, the same process takes place in the same order:
+- The Node backed by that Machine will try to be drained indefinitely and will wait for any volume to be detached from the Node unless you specify a .spec.nodeDrainTimeout.
+  - CAPI uses default [kubectl draining implementation](https://kubernetes.io/docs/tasks/administer-cluster/safely-drain-node/) with –ignore-daemonsets=true. If you needed to ensure DaemonSets eviction you'd need to do so manually by also adding proper taints to avoid rescheduling.
+- The infrastructure backing that Node will try to be deleted indefinitely.
+- Only when the infrastructure is gone, the Node will try to be deleted indefinitely unless you specify spec.nodeDeletionTimeout.