- Use `properties.hidden` directly instead of passing it around.
- Disambiguate `isHidden` to `requestShow` in `_toggleDisplay`.
- Create an export base classes from Menu and MenuItem.
- Remove underscore prefix from protected class members.
- Fix doc comments for Menu/MenuItem properties.
- Fix MenuItem child type.

- Remove the ability to specify `animate` as a function.
- Remove `getAriaProperties` in favor of individual properties.
- Simplify the MenuItem widget.

- Remove unused import
- Remove menu/example.html
- Fix example page
- Use `KeyboardEvent#keyCode` where `key` is unavailable
- Consolidate menu CSS into a single module
- Ensure menu is scrolled to top when animating open

- Use `onElementCreated` and `onElementUpdated`
- Correct use of `KeyboardEvent#keyCode`
- Privacy updates

`MenuItem`:
- Allow tag and vnode properties to be set.
- Fix ARIA properties.
- Allow different `role`s to be applied.

`Menu`:
- Update keyboard handling to more accurately match the WAI-ARIA spec.
- Add handling for right/left arrows, space key.
- Internalize active index management.
- Add an `orientation` property.

- Rename event listener names for consistency with other widgets.
- Change `container`/`nestedMenuContainer` CSS classes to
  `root`/`nestedMenuRoot`, respectively.
- Use CSS variable for menu animation duration.
- Simplify function property checks.
- Only move focus from the label into the menu when navigating via the
  keyboard.
- Add `hideOnActivate` options.
- Always expand submenus when the designated "descend" key is pressed.

- general cleanup
- remove tabIndex from menu container
- reset active index on hide
- move focus on click

- Prevent the default action when the down arrow key is pressed while
  the menu trigger is focused.
- Add `parentOrientation` property to ensure that vertical submenus of
  horizontal menus are opened with down arrow key instead of the right
  arrow key.

Simplify the `Menu` widget to do nothing more than render a list of menu
children and manage the keyboard/mouse event interactions with them.
Create a separate `SubMenu` widget that renders a menu item that
toggles the menu in-and-out of view.

Update `SubMenu` with dropdown functionality and the beginnings of popup
functionality.

- Add guard to focusout handler to prevent destroyed widgets from being
  manually inactivated.
- Change `animate` to `animation`.
- Toggle menu with space key.
- `MenuItem`s default to `a` tag.
- Implement `hideOnBlur` property.
- Respond to submenu key events only when active
- Update privacy of MenuItem methods.
- Stop propagation when an arrow key is pressed on a SubMenu trigger to
  prevent navigation within a parent menu.
- Focus menu items within a rAF call in order to give any animations
  time to complete.

Update the focus logic in `MenuItem` to account for browsers that
require more than one task to mark as visible elements being animated
from `visibility: hidden`. Also update Menu readme.

Put a cap on how many frames `MenuItem` will wait before ceasing to wait
for its DOM node to become hidden.

- Improve popup logic and add an example.
- Activate menu items when the enter key is pressed.
- Add a `menuId` property to `MenuItem` so that ancestor menus can
  ignore clicks within nested menus.

Replace the `fadeIn`/`fadeOut` keyframes with a simpler transition (h/t
@smhigley).

- Use spaces for the TypeDoc comments.
- Remove unneeded `nested` property.
- Create common `Keys` and `observeViewport` utilities.
- Allow slide pane trigger to be a DNode.

Replace the `menuId` property from `MenuItem` with a `onMouseDown`
property, and update event-related properties to accept both the event
and an optional `index`.

- Fix util tests
- Use updated `Keys` enum
- Remove variables.css.d.ts

- Convert `Orientation` to an enum
- Add custom element descriptors
- Only create a default menu id when the property is missing