feat(SKE): support for DNS extension (#492)

* Feat(SKE): support DNS extension

* generate docs

* fix attributes required/optional

* add comment to acceptance test DNS zones

* regenerate docs

* fix typos

* generate docs

docs/resources/ske_cluster.md

@@ -115,17 +115,15 @@ Optional:
 
 - `acl` (Attributes) Cluster access control configuration. (see [below for nested schema](#nestedatt--extensions--acl))
 - `argus` (Attributes) A single argus block as defined below. (see [below for nested schema](#nestedatt--extensions--argus))
+- `dns` (Attributes) DNS extension configuration (see [below for nested schema](#nestedatt--extensions--dns))
 
 <a id="nestedatt--extensions--acl"></a>
 ### Nested Schema for `extensions.acl`
 
 Required:
 
-- `enabled` (Boolean) Is ACL enabled?
-
-Optional:
-
 - `allowed_cidrs` (List of String) Specify a list of CIDRs to whitelist.
+- `enabled` (Boolean) Is ACL enabled?
 
 
 <a id="nestedatt--extensions--argus"></a>
@@ -133,11 +131,20 @@ Optional:
 
 Required:
 
+- `argus_instance_id` (String) Argus instance ID to choose which Argus instance is used. Required when enabled is set to `true`.
 - `enabled` (Boolean) Flag to enable/disable Argus extensions.
 
+
+<a id="nestedatt--extensions--dns"></a>
+### Nested Schema for `extensions.dns`
+
+Required:
+
+- `enabled` (Boolean) Flag to enable/disable DNS extensions
+
 Optional:
 
-- `argus_instance_id` (String) Argus instance ID to choose which Argus instance is used. Required when enabled is set to `true`.
+- `zones` (List of String) Specify a list of domain filters for externalDNS (e.g., `foo.runs.onstackit.cloud`)