Syntax highlighting of server-protocol/Packet_0x1D

# Packet 0x1D

The server sends clients a Packet 0x1D as a "ping" packet (essentially to make sure that the client is still alive). The client should reply with an identical packet.

## Dreamcast Packet Format
| Bytes | Meaning |
| --- | --- |
| 0x00 | Packet Type (0x1D) |
| 0x01 | Flags (0x00) |
| 0x02-0x03 | Packet Size (0x0004) |