Add Windows documentation note

Author: prvyk

website/docs/dev/onboarding.md

@@ -63,6 +63,7 @@ dotnet run -c Debug -f net8.0 -- --logger-level Trace -m 4g -i 64m
 6. A third option is to install Redis-Insight on Windows. Follow the official guide [here](https://redis.com/redis-enterprise/redis-insight/#insight-form).
 
 7. A fourth option is to connect with telnet and just type commands. However, telnet does not decode the responses, you'll see the raw RESP serialization.
+On Windows, telnet defaults to localecho off, a user won't see their typing until after first command is sent. Alternatively, a user can type Ctrl-] followed by Enter, and telnet will start echoing.
 
 ```bash
     telnet localhost 6379