Feature Request: El Torito Support

[Simon Lehn]

I would love to see El Torito being supported.
El Torito images are valid ISO9660 images with the addition of being able to be written to USB drives (dd) for example.

links:

https://wiki.osdev.org/El-Torito

https://en.wikipedia.org/wiki/El_Torito_(CD-ROM_standard)

https://github.com/diskfs/go-diskfs/blob/1f72a0e0bb68b80c9659e81940962171e9dc9aed/filesystem/iso9660/eltorito.go

Thanks for creating this library!