checkbox and switch should allow aria-expanded

[mitchellevan]

Current

https://w3c.github.io/html-aria/#allowed-aria-roles-states-and-properties

• The checkbox role does not allow aria-expanded.
• The switch role does not allow aria-expanded.

However, the ARIA Editor's Draft allows them.

• https://w3c.github.io/aria/#checkbox
• https://w3c.github.io/aria/#switch

Proposed

Add aria-expanded in the Supported Properties column for checkbox and switch.

[scottaohara]

This, among many other updates pertaining to alignment with ARIA 1.2, will be addressed in PR #198

[mitchellevan]

@scottaohara Feel free to leave this issue open for tracking, or close it if it's sufficiently tracked in #192 or elsewhere

[scottaohara]

it's a good reminder / allows others to know aria 1.2 updates are coming. going to leave it open.

[scottaohara]

this section of the table has been removed, so this issue is no longer relevant.