MAINT: document on disable_refresh secret extension setting

Signed-off-by: George Chen <[email protected]>

_data-prepper/managing-data-prepper/configuring-data-prepper.md

@@ -128,6 +128,7 @@ extensions:
         region: <YOUR_REGION_1>
         sts_role_arn: <YOUR_STS_ROLE_ARN_1>
         refresh_interval: <YOUR_REFRESH_INTERVAL>
+        disable_refresh: false
       <YOUR_SECRET_CONFIG_ID_2>:
         ...
 ```
@@ -148,7 +149,8 @@ Option | Required | Type | Description
 secret_id  | Yes | String | The AWS secret name or ARN.                                                                                                                                                                                              |
 region | No | String   | The AWS region of the secret. Defaults to `us-east-1`.                                                                                                                                                                            
 sts_role_arn | No | String   | The AWS Security Token Service (AWS STS) role to assume for requests to the AWS Secrets Manager. Defaults to `null`, which will use the [standard SDK behavior for credentials](https://docs.aws.amazon.com/sdk-for-java/latest/developer-guide/credentials.html). 
-refresh_interval | No | Duration | The refreshment interval for AWS secrets extension plugin to poll new secret values. Defaults to `PT1H`. See [Automatically refreshing secrets](#automatically-refreshing-secrets) for details.                             
+refresh_interval | No | Duration | The refreshment interval for AWS secrets extension plugin to poll new secret values. Defaults to `PT1H`. See [Automatically refreshing secrets](#automatically-refreshing-secrets) for details.
+disable_refresh | No | Boolean | The flag to disable AWS secrets extension plugin regular polling on latest secret values. Defaults to `false`. When set to `true`, `refresh_interval` will not be used.
 
 #### Reference secrets
 ß