docs(apigateway): address leandro's feedback on replacing POWERTOOLS_EVENT_HANDLER_DEBUG

Author: heitorlessa

docs/core/event_handler/api_gateway.md

@@ -388,7 +388,7 @@ Like `compress` feature, the client must send the `Accept` header with the corre
 
 ### Debug mode
 
-You can enable debug mode via `debug` param, or via `POWERTOOLS_EVENT_HANDLER_DEBUG` [environment variable](../../index.md#environment-variables).
+You can enable debug mode via `debug` param, or via `POWERTOOLS_DEV` [environment variable](../../index.md#environment-variables).
 
 This will enable full tracebacks errors in the response, print request and responses, and set CORS in development mode.