Set user-chosen keyboard layout data.
a keyboard layout map according to https://wicg.github.io/keyboard-map/
Test all known keyboard layouts with the given combination of pressed key and produced character. Matching layouts have their score increased (see class KeyboardTester). If this leads to a change of the top-scoring layout, a layout change event is fired.
Select a layout based on the current tester state and the operating system and language detected from the browser.