Create initial multiplayer server skeleton

rc_multiplayer/src/data/net_msg_ty.rs

@@ -0,0 +1,18 @@
+#[repr(i16)]
+#[derive(Debug, Clone, Copy)]
+pub enum MessageType {
+    ClientMsg = 48,
+    ServerMsg = 49,
+    RobotMotion = 50,
+}
+
+impl MessageType {
+    pub fn from_i16(num: i16) -> Option<Self> {
+        match num {
+            48 => Some(Self::ClientMsg),
+            49 => Some(Self::ServerMsg),
+            50 => Some(Self::RobotMotion),
+            _ => None,
+        }
+    }
+}