* Add tree-control expand/collapse on click the expander button or by a custom logic
* Upgrade WP components dependency to v19.8.5 to support indeterminate checkbox control
* Add styles to fit the disign
* Add tree-control expand/collapse on click the expander button or by a custom logic
* Add a11y landmarks
* Add keyboard interactions
* Add changelog file
* Fix linter errors
* Resolving rebase conflicts
* Add comment suggestions