add secret redactor example

Signed-off-by: zeshanziya <zeshan.ziya@axelerant.com>

docs/backend-system/core-services/root-logger.md

@@ -18,6 +18,7 @@ The following example is how you can override the root logger service to add add
 ```ts
 import { coreServices } from '@backstage/backend-plugin-api';
 import { WinstonLogger } from '@backstage/backend-defaults/rootLogger';
+import { createConfigSecretEnumerator } from '@backstage/backend-defaults/rootConfig';
 
 const backend = createBackend();
 
@@ -43,6 +44,12 @@ backend.add(
         transports: [new transports.Console()],
       });
 
+      const secretEnumerator = await createConfigSecretEnumerator({
+        logger,
+      });
+      logger.addRedactions(secretEnumerator(config));
+      config.subscribe?.(() => logger.addRedactions(secretEnumerator(config)));
+
       return logger;
     },
   }),