Add link to upgrade guide

Author: pedrosousa

src/content/docs/waf/detections/leaked-credentials/index.mdx

@@ -9,6 +9,10 @@ sidebar:
 
 The leaked credentials [traffic detection](/waf/detections/) scans incoming requests for previously leaked credentials (usernames and passwords) previously leaked from data breaches.
 
+:::note
+If you are currently using [Exposed Credentials Check](/waf/managed-rules/check-for-exposed-credentials/) (a previous implementation) and want to upgrade to leaked credentials detection, refer to our [upgrade guide](/waf/managed-rules/check-for-exposed-credentials/upgrade-to-leaked-credentials-detection/).
+:::
+
 ## How it works
 
 Once enabled, leaked credentials detection will scan incoming HTTP requests for known authentication patterns from common web apps and any custom detection locations you configure.