Autocomplete's aria-live region should clear itself out so it can't be navigated to

[WestonThayer]

This happens in any screen reader. For example, with NVDA + Firefox:

1. Go to https://nostyle.herokuapp.com/examples/autocomplete
2. Tab to the control to focus it and type "states"
3. Use NVDA + SPACE to switch out of forms mode and into browse mode
4. Press ARROW_DOWN. Virtual cursor will be moved to the little dropdown arrow, which announces as "clickable" (could be an issue in and of itself)
5. Press ARROW_DOWN again

Virtual cursor is moved to the hidden aria-live region, where user hears "3 results".

This can be fixed by clearing out the contents of the aria-live region 500ms after it's been added.

[WestonThayer]

Also, sorry if you're not looking for issues yet! Your awesome library was linked to in the web-a11y Slack. I was totally impressed by autocomplete!

[adamsilver]

Thanks a lot for this @WestonThayer