* encode expected `aria-expanded` behaviour
* ensure `aria-expanded` has the correct value
`aria-expanded` can be in 3 different states:
| Value | Description |
| ------------------- | -------------------------------------------------------------------------- |
| false | The grouping element this element owns or controls is collapsed. |
| true | The grouping element this element owns or controls is expanded. |
| undefined (default) | The element does not own or control a grouping element that is expandable. |
Ref: https://www.w3.org/TR/wai-aria-1.2/#aria-expandedFixes: #580
* ensure `disabled` prop in Vue is not rendered when `false`
* update changelog
Robin Malfait
045b843f5b