Where can I find the Channel Packaging and Publishing Guide?

Hi all,
I am trying to find the Channel Packaging and Publishing Guide referenced in many, many locations.
One would expect this to be linked in https://owner.roku.com/Developer/DevHome in “Essential Reading”, but no luck.
Can someone point me to the correct location?

Thanks.

Download the SDK. The “Download All” link in the page you linked. All of the documentation will be in the documents folder of the zip file.