Additions from Blurb

Hi Erik,

Huge thank-you from all of us here at Blurb for creating this gem!
Navigating through the Amazon specs was tough-going for us, and we
wouldn't have hit our deadlines without your efforts.

We've made a few additions for your consideration. If you see
anything amiss, or if you have any suggestions on how we can be
better contributors to your project, please let us know and we'll
do our best.

Summary of changes:
* Add shipping and order confirmation acknowledgements
* Add product endpoint
* Move MarkerplaceId lists to specific requests

Thanks,
Chris