add service binding to argument name example

Author: kbond

service_container.rst

@@ -638,6 +638,10 @@ You can also use the ``bind`` keyword to bind specific arguments by name or type
                     # pass this value to any $adminEmail argument for any service
                     # that's defined in this file (including controller arguments)
                     $adminEmail: '[email protected]'
+                    
+                    # pass this service to any $requestLogger argument for any
+                    # service that's defined in this file
+                    $requestLogger: '@monolog.logger.request'
 
                     # pass this service for any LoggerInterface type-hint for any
                     # service that's defined in this file