A sample letter for response to the Low Vis Req Doc

Hi All,
https://github.com/w3c/low-vision-a11y-tf/issues/47

Contains a sample letter with the list of user requirements out to the
Council of Citizens with Low Vision. I thought it might be a good format to
send out to other lists.

Could some of you. (1) fact check it, (2) check to see if the simple
language is really simpler.

Wayne