implement syncing world to file on disk

include/serialize.h

@@ -0,0 +1,21 @@
+#ifndef SERIALIZE_H
+#define SERIALIZE_H
+
+#include <stdlib.h>
+
+#include "globals.h"
+
+#if defined(SYNC_WORLD_TO_DISK) && !defined(ESP_PLATFORM)
+  int initSerializer ();
+  void writeBlockChangesToDisk (int from, int to);
+  void writeChestChangesToDisk (uint8_t *storage_ptr, uint8_t slot);
+  void writePlayerDataToDisk ();
+#else
+  // Define no-op placeholders for when disk syncing isn't enabled
+  #define writeBlockChangesToDisk(a, b)
+  #define writeChestChangesToDisk(a, b)
+  #define writePlayerDataToDisk()
+  #define initSerializer() 0
+#endif
+
+#endif