Isolate-Me explainer

Hi webappsec! Mike, Joel, and I have been discussing an idea for a
developer facing opt-in to allow highly security- or privacy-sensitive
sites to be isolated from other origins on the web.

We wrote up the idea here to explain what we're thinking about, why we
think it's important, and the major open questions:
https://mikewest.github.io/isolation/explainer.html

Please read and comment/criticize/etc. Thoughts welcome, either here in
this thread or as GitHub issues. Especially interested to hear from Mozilla
folks as it relates to and is heavily inspired by containers.

Thanks!
Emily