Update eck pdb docs (elastic#2361)

The following elastic/cloud-on-k8s#8780 is
planned to be released with the ECK 3.2/Stack 9.2 release. 

---------

Signed-off-by: Michael Montgomery <[email protected]>

Author: naemono

deploy-manage/deploy/cloud-on-k8s/pod-disruption-budget.md

@@ -12,9 +12,47 @@ products:
 
 A [Pod Disruption Budget](https://kubernetes.io/docs/tasks/run-application/configure-pdb/) (PDB) allows you to limit the disruption to your application when its pods need to be rescheduled for some reason such as upgrades or routine maintenance work on the Kubernetes nodes.
 
-ECK manages a default PDB per {{es}} resource. It allows one {{es}} Pod to be taken down, as long as the cluster has a `green` health. Single-node clusters are not considered highly available and can always be disrupted.
+{{eck}} manages either a single default PDB, or multiple PDBs per {{es}} resource depending on the license level of the ECK installation.
 
-In the {{es}} specification, you can change the default behavior as follows:
+:::{note}
+In {{eck}} 3.1 and earlier, all clusters follow the [default PodDisruptionBudget rules](#default-pdb-rules), regardless of license type.
+:::
+
+## Advanced rules (Enterprise license required)
+```{applies_to}
+deployment:
+  eck: ga 3.2
+```
+
+In Elasticsearch clusters managed by ECK and licensed with an Enterprise license, a separate PDB is created for each type of `nodeSet` defined in the manifest. This setup allows Kubernetes upgrade or maintenance operations to be executed more quickly. Each PDB permits one Elasticsearch Pod per `nodeSet` to be disrupted at a time, provided the Elasticsearch cluster maintains the health status described in the following table:
+
+| Role | Cluster health required | Notes |
+|------|------------------------|--------|
+| master | Yellow |  |
+| data | Green | All Data roles are grouped together into a single PDB, except for data_frozen. |
+| data_frozen | Yellow | Since frozen data tier nodes only host partially mounted indices backed by searchable snapshots additional disruptions are allowed. |
+| ingest | Yellow |  |
+| ml | Yellow |  |
+| coordinating | Yellow |  |
+| transform | Yellow |  |
+| remote_cluster_client | Yellow |  |
+
+Single-node clusters are not considered highly available and can always be disrupted regardless of license type.
+
+## Default rules (Basic license) [default-pdb-rules]
+:::{note}
+In {{eck}} 3.1 and earlier, all clusters follow this behavior regardless of license type.
+:::
+
+In {{eck}} clusters that do not have an Enterprise license, one {{es}} Pod can be taken down at a time, as long as the cluster has a health status of `green`. Single-node clusters are not considered highly available and can always be disrupted.
+
+## Overriding the default behavior
+
+In the {{es}} specification, you can change the default behavior in two ways. By fully overriding the PodDisruptionBudget within the {{es}} spec or by disabling the default PodDisruptionBudget and specifying one or more PodDisruptionBudget(s).
+
+### Specify your own PodDisruptionBudget [k8s-specify-own-pdb]
+
+You can fully override the default PodDisruptionBudget by specifying your own PodDisruptionBudget in the {{es}} spec.
 
 ```yaml
 apiVersion: elasticsearch.k8s.elastic.co/v1
@@ -34,14 +72,15 @@ spec:
           elasticsearch.k8s.elastic.co/cluster-name: quickstart
 ```
 
-::::{note} 
+This will cause the ECK operator to only create the PodDisruptionBudget defined in the spec. It will not create any additional PodDisruptionBudgets.
+
+::::{note}
 [`maxUnavailable`](https://kubernetes.io/docs/tasks/run-application/configure-pdb/#arbitrary-controllers-and-selectors) cannot be used with an arbitrary label selector, therefore `minAvailable` is used in this example.
 ::::
 
+### Create a PodDisruptionBudget per nodeSet [k8s-pdb-per-nodeset]
 
-## Pod disruption budget per nodeset [k8s-pdb-per-nodeset]
-
-You can specify a PDB per nodeset or node role.
+You can specify a PDB per `nodeSet` or node role.
 
 ```yaml subs=true
 apiVersion: elasticsearch.k8s.elastic.co/v1
@@ -81,6 +120,3 @@ spec:
 4. Pod disruption budget applies on all master nodes.
 5. Specify pod disruption budget to have 1 hot node available.
 6. Pod disruption budget applies on nodes of the same nodeset.
-
-
-