source: pub fn new in async zip reader

lib/src/source.rs

@@ -313,7 +313,7 @@ pub mod reader_async {
     where
         R: AsyncRead + AsyncSeek + Unpin,
     {
-        fn new(zipfile: ZipFileReader<R>) -> Self {
+        pub fn new(zipfile: ZipFileReader<R>) -> Self {
             SourceQuestionsZipReaderAsync {
                 zipfile,
                 index: None,