[Modify] Edit it

README.md

@@ -450,7 +450,7 @@ wssv.AddWebSocketService<Chat> (
 );
 ```
 
-If it's set to `true`, the server doesn't return the **Sec-WebSocket-Extensions** header in its response.
+If it's set to `true`, the service will not return the **Sec-WebSocket-Extensions** header in its handshake response.
 
 I think this is useful when you get something error in connecting the server and exclude the extensions as a cause of the error.