Hitting ESC should work inside of menu, change <h1> to <h2>

Testing with macOS Safari +  VoiceOver and keyboard navigation, seems pretty decent to get to the list of search results, but then you can't hit ESC to exit out of the results, so you sort of get stuck in there.

Also, hearing "heading level 1" for each item feels strange. Probably makes more sense as `<h2>` tags even though you're inside of shadow DOM.