[uievents-key] Don't list modifier keys in the uievents spec (link to uievents-key instead) (#15)

In https://w3c.github.io/uievents/#event-constructors, there is a list of modifier keys -- all of them except the 4 that have special xxxKey flags.

Rather than enumerating them here, there should be a link to https://w3c.github.io/uievents-key/#keys-modifier.



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Reply to this email directly or view it on GitHub:
https://github.com/w3c/uievents-key/issues/15