rearrange source/header files for compatibility with CocoaPods Framework structure

ios/include/ResourceBuffer.hpp

@@ -0,0 +1,44 @@
+#ifndef RESOURCE_BUFFER_H
+#define RESOURCE_BUFFER_H
+
+#include <stdint.h>
+#if defined(__cplusplus)
+extern "C" {
+#endif
+    // 
+    // Pairs a memory buffer with an ID that can be used to unload the backing asset if needed.
+    // Use this when you want to load an asset from a resource that requires more than just `free` on the underlying buffer.
+    // e.g. 
+    // ```
+    // uint64_t id = get_next_resource_id();
+    // AAsset *asset = AAssetManager_open(am, name, AASSET_MODE_BUFFER);
+    // off_t length = AAsset_getLength(asset);
+    // const void * buffer = AAsset_getBuffer(asset);
+    // uint8_t *buf = new uint8_t[length ];
+    // memcpy(buf,buffer,  length);
+    // ResourceBuffer rb(buf, length, id);
+    // ...
+    // ...
+    // (elsewhere)
+    // AAsset* asset = get_asset_from_id(rb.id);
+    // AAsset_close(asset);
+    // free_asset_id(rb.id);
+    //
+    struct ResourceBuffer {
+        #if defined(__cplusplus)
+        ResourceBuffer(const void* data, const uint32_t size, const uint32_t id) : data(data), size(size), id(id) {};
+        ResourceBuffer& operator=(ResourceBuffer other) {
+          data = other.data;
+          size = other.size;
+          id = other.id;
+          return *this;
+        }
+        #endif
+        const void* data;
+        uint32_t size;
+        uint32_t id;
+    };
+#if defined(__cplusplus)
+}
+#endif
+#endif