add narrator table

[stevefaulkner]

add table with info about windows narrator support for html and keystrokes and recordings, dunno whether its better to use IE or Edge?

@dstorey any thoughts?

[dstorey]

Better to use Edge as it will be the main focus going forward. Edge 13 should already have a number of improvements. Edge 14 (next version) will have most of the improvements (the HTML mappings to UIA, etc.)