Update on Google's NXT prototype

Hey all,

This is just a heads up that we have written an overview document for NXT
<https://docs.google.com/document/d/1-lAvR9GXaNJiqUIpm3N2XuGUWv_JrkpGizDN0bNq7wY>,
if you want to take a look. It describes its philosophical goals and
design, so that it is easier for everyone (including us) to reason about
NXT in the upcoming discussions.

In other news, we created the google/nxt-standalone
<https://github.com/google/nxt-standalone> GitHub repository were upstream
work will happen, and we'll update gpuweb/nxt-standalone
<https://github.com/gpuweb/nxt-standalone> periodically. We recently added
"resource usage transitions" that are the equivalent of memory barriers and
layout changes in native APIs, and are looking at API errors and render
passes next.

Cheers,

Corentin