Support Apple Watch web pages

[philwareham]

See: https://developer.apple.com/videos/play/wwdc2018/239/

Summary:

• Use aria-label attributes in inputs fields.
• Layout and meta amends.
• Probably other stuff.

I don't have an Apple Watch to test on yet - but I may acquire one when watchOS 5 drops.

[cara-tm]

I'm excited and curious about how you can achieve such a thing!