Expose yyjson_doc_get_read_size?

[dsully]

Hi - for reading NDJSON / JSONL files with ReaderFlags.STOP_WHEN_DONE - is not extremely easy as the read size that yyjson consumed is not available for the caller.

yyjson_doc_get_read_size() can do this- Perhaps as a .size or .read_bytes on Document ?

Thanks