Replace links to kaitai_struct GitHub wiki with doc.kaitai.io

Author: generalmimon

README.md

@@ -9,4 +9,4 @@ formats, network stream packet formats, etc.
 Further reading:
 
 * [About Kaitai Struct](https://github.com/kaitai-io/kaitai_struct/)
-* [About API implemented in this library](https://github.com/kaitai-io/kaitai_struct/wiki/Kaitai-Struct-stream-API)
+* [About API implemented in this library](https://doc.kaitai.io/stream_api.html)

lib/IO/KaitaiStruct.pod

@@ -45,7 +45,7 @@ Further reading:
 
 =item L<About Kaitai Struct|https://github.com/kaitai-io/kaitai_struct/>
 
-=item L<About API implemented in this library|https://github.com/kaitai-io/kaitai_struct/wiki/Kaitai-Struct-stream-API>
+=item L<About API implemented in this library|https://doc.kaitai.io/stream_api.html>
 
 =back