Move messages to their own headers

include/robomaster.h

@@ -0,0 +1,15 @@
+#pragma once
+
+#include <stdlib.h>
+#include <stddef.h>
+#include <inttypes.h>
+#include <stdbool.h>
+
+// Public stuff
+struct Message;
+struct Client;
+typedef struct Client* Client;
+typedef struct Message* Message;
+
+Client client_new(void* buffer, size_t size);
+