New feature incubation repo: DOM overlays

Hello, immersive web folks.

After conversations in person and in Issues 50
<https://github.com/immersive-web/proposals/issues/50> and 400
<https://github.com/immersive-web/webxr/issues/400>, I've created a new
repo for the incubation of a DOM overlay
<https://github.com/immersive-web/dom-overlays>.

The feature lead for this new repo is John Pallett (@JohnPallett on GitHub)
from Google. He will organize the writing of an initial explainer document
that describes the context for the feature and links to any existing work.

If you would like to be a part of writing the explainer then you should
reach out to John.

Stay open,

- Trevor

-- 

*Trevor Flowers* 🌸🌸
trevor@transmutable.com
Principal at Transmutable <https://transmutable.com/>
Friend of the Wider Web <https://potassiumes.org/wider-web/>