Queues a packet to be sent to the peer.
peer:send(data, channel, flag)
- The contents of the packet, it must be a string.
- The channel to send the packet on. Optional. Defaults to 0.
- flag is one of "reliable", "unsequenced", or "unreliable". Reliable packets are guaranteed to arrive, and arrive in the order in which they are sent. Unreliable packets arrive in the order in which they are sent, but they aren't guaranteed to arrive. Unsequenced packets are neither guaranteed to arrive, nor do they have any guarantee on the order they arrive. Optional. Defaults to reliable.