Added a very complicated AsyncIterableReader class.

The class was already implemented in
"https://deno.land/std@0.144.0/streams/conversion.ts".  So, I litterally
lost 1 day of work!  I hate myself.

vendor/deno.land/std@0.188.0/io/read_short.ts

@@ -0,0 +1,15 @@
+// Copyright 2018-2023 the Deno authors. All rights reserved. MIT license.
+
+import { type BufReader } from "./buf_reader.ts";
+
+/**
+ * Read big endian 16bit short from BufReader
+ * @param buf
+ */
+export async function readShort(buf: BufReader): Promise<number | null> {
+  const high = await buf.readByte();
+  if (high === null) return null;
+  const low = await buf.readByte();
+  if (low === null) throw new Deno.errors.UnexpectedEof();
+  return (high << 8) | low;
+}