Update ChromeOS Docs
Update ChromeOS Docs

Reflecting the new repository, supported workflows
and code submission process.

BUG=b:239255196
TEST=None

Change-Id: I52d7130ec3d72ea5ef8748875cae029f0b1f701b
Reviewed-on: https://chromium-review.googlesource.com/c/crosvm/crosvm/+/3780864
Auto-Submit: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>
Tested-by: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>
Commit-Queue: Dennis Kempin <cd09796fb571bec2782819dbfd33307f65b1c778@google.com>
Reviewed-by: Daniel Verkamp <72bc170b46ec491f7bdd4359a1c0bfed274de40c@chromium.org>

google/crosvm,google/crosvm,google/crosvm,google/crosvm