fix keyboard event repeat property

[snowystinger]

What

Closes Keyboard: Press and hold for X events does not set the 'repeated' attribute

Why

I was unable to test repeat key enabled handlers in our repo. fix: all keyboard repeat events for navigation
I was writing sequences like

fireEvent.keydown(document.activeElement, {key: 'a'});
fireEvent.keydown(document.activeElement, {key: 'a', repeat: true});
fireEvent.keyup(document.activeElement, {key: 'a'});

How

When the key has not been released and has fired more than 1 event, it includes the repeat property set to true.

Checklist

• Documentation
• Tests
• Ready to be merged

The documentation already says it handles repeat keys. It was unexpected that it didn't set the property.