[FLINK-37391][docs] Improve documentation for dynamic namespace watching configuration

- Add example configuration for enabling dynamic namespace watching
- Clarify that dynamic.namespaces.enabled requires dynamic.config.enabled to be true

Author: kumar-mallikarjuna

docs/content.zh/docs/operations/configuration.md

@@ -86,6 +86,18 @@ Verify whether the config value of `kubernetes.operator.reconcile.interval` is u
 2022-05-28 13:08:30,115 o.a.f.k.o.c.FlinkConfigManager [INFO ] Updating default configuration to {kubernetes.operator.reconcile.interval=PT30S}
 ```
 
+### Example: Enabling Dynamic Namespace Watching
+
+To allow the operator to react to changes in the `watchNamespaces` list dynamically, i.e., without restarting its pod, you must set both of the following in your configuration:
+
+```yaml
+# 1. Enable the global dynamic configuration feature
+kubernetes.operator.dynamic.config.enabled: true
+
+# 2. Enable the specific feature for dynamic namespaces
+kubernetes.operator.dynamic.namespaces.enabled: true
+```
+
 ## Leader Election and High Availability
 
 The operator supports high availability through leader election and standby operator instances. To enable leader election you need to add the following two mandatory operator configuration parameters.

docs/layouts/shortcodes/generated/kubernetes_operator_config_configuration.html

@@ -96,7 +96,7 @@
             <td><h5>kubernetes.operator.dynamic.namespaces.enabled</h5></td>
             <td style="word-wrap: break-word;">false</td>
             <td>Boolean</td>
-            <td>Enables dynamic change of watched/monitored namespaces.</td>
+            <td>Enables the operator to dynamically update the list of namespaces it watches. Requires dynamic.config.enabled to be set to true.</td>
         </tr>
         <tr>
             <td><h5>kubernetes.operator.events.exceptions.limit-per-reconciliation</h5></td>

docs/layouts/shortcodes/generated/system_section.html

@@ -12,7 +12,7 @@
             <td><h5>kubernetes.operator.dynamic.namespaces.enabled</h5></td>
             <td style="word-wrap: break-word;">false</td>
             <td>Boolean</td>
-            <td>Enables dynamic change of watched/monitored namespaces.</td>
+            <td>Enables the operator to dynamically update the list of namespaces it watches. Requires dynamic.config.enabled to be set to true.</td>
         </tr>
         <tr>
             <td><h5>kubernetes.operator.exception.field.max.length</h5></td>

flink-kubernetes-operator/src/main/java/org/apache/flink/kubernetes/operator/config/KubernetesOperatorConfigOptions.java

@@ -404,7 +404,8 @@ public static String operatorConfigKey(String key) {
             operatorConfig("dynamic.namespaces.enabled")
                     .booleanType()
                     .defaultValue(false)
-                    .withDescription("Enables dynamic change of watched/monitored namespaces.");
+                    .withDescription(
+                            "Enables the operator to dynamically update the list of namespaces it watches. Requires dynamic.config.enabled to be set to true.");
 
     @Documentation.Section(SECTION_SYSTEM)
     public static final ConfigOption<Duration> OPERATOR_RETRY_INITIAL_INTERVAL =