Proposal for the WebPerf Workshop: Client-Hints for better server-side content adaption

Hello all! Would like to propose a topic to discuss during the Nov 8th
webperf workshop: "client-hints".

*Problem*: adapting site content based on device DPI, screen size, etc,
incurs additional latency and hides resources from the client (when done
via JS).

This is a problem that has come up on many occasions and the current
solutions, which are based on User-Agent parsing are inadequate: not cache
friendly, error prone, hard to maintain and deploy, and the list goes on.
To that end, a quick draft proposal:

https://docs.google.com/document/d/1xCtGvPbvVLacg45MWdAlLBnuWa7sJM1cEk1lI6nv--c/edit#

Please feel free to edit or comment - would love to hear your feedback.

Ilya