[JasperM]

The easiest way I could guess of doing it is the following:

1. Set up a TCP server.
2. Create a Discord bot that relays the messages from Discord to the TCP server as a client.
3. In your gamemode or filterscript, run another TCP client that sends the SA-MP messages to the TCP server.
4. Send the messages from the SA-MP server to the Discord Bot which shows it in Discord, and make Discord messages show up in the SA-MP server.

I don't have time to write this, unfortunately, but this is how I would do it I guess.