Adds a link to the update cross cluster API key API spec (#4649)

* Adds a link to the update cross cluster API key API spec.

* Fix format.

* Run make spec-format-fix

* Update specification/security/update_cross_cluster_api_key/UpdateCrossClusterApiKeyRequest.ts

---------

Co-authored-by: Quentin Pradet <[email protected]>

Author: szabosteve

specification/security/update_cross_cluster_api_key/UpdateCrossClusterApiKeyRequest.ts

@@ -40,6 +40,8 @@ import { Access } from '@security/_types/Access'
  * The owner user's information, such as the `username` and `realm`, is also updated automatically on every call.
  *
  * NOTE: This API cannot update REST API keys, which should be updated by either the update API key or bulk update API keys API.
+ *
+ * To learn more about how to use this API, refer to the [Update cross cluter API key API examples page](https://www.elastic.co/docs/reference/elasticsearch/rest-apis/update-cc-api-key-examples).
  * @rest_spec_name security.update_cross_cluster_api_key
  * @availability stack stability=stable
  * @cluster_privileges manage_security