docs: add backticks around 'secrets' in command group docstring

Co-Authored-By: Aaron <AJ> Steers <[email protected]>

Author: devin-ai-integration[bot]

airbyte_cdk/cli/airbyte_cdk/_secrets.py

@@ -37,7 +37,7 @@ def secrets_cli_group() -> None:
         airbyte-cdk secrets fetch  # Run from within a connector directory
 
     The 'fetch' command retrieves secrets from Google Secret Manager based on connector
-    labels and writes them to the connector's secrets directory.
+    labels and writes them to the connector's `secrets` directory.
     """
     pass