site-amd64-hw: Add README

BUG=None
TEST=None
RELEASE_NOTE=None

Change-Id: I896b12ec3a1052be3799a368bb88e46bd3233164
Reviewed-on: https://cos-review.googlesource.com/c/cos/overlays/board-overlays/+/8820
Tested-by: Robert Kolchmeyer <rkolchmeyer@google.com>
Reviewed-by: Saied Kazemi <saied@google.com>
Reviewed-by: Ismael Aleman <ialeman@google.com>
1 file changed