UCR progress

Github seems to be pushing the updates:

https://w3c.github.io/dxwg/ucr/

now has a better consolidated and cross-referenced set of requirements,
along with other edits.  Requirements are referenced back to the source use
cases in most cases, but use cases arent yet forward referenced to
requirements.

  I'd say we are at about 70% of editorial work to have a first draft of
requirements deduplicated as much as possible without further discussion,
and cross referenced and formatted neatly.

We will need to review these requirements of course to make sure nothing
has been missed, and requirements are in fact adequately justified by the
use cases. Feel free to review these and create PRs to forward-reference
your UC to the requirements, send me a list or wait for the UCR editors to
get around to this.

Rob Atkinson