Accessibility support matrix for all components

[mrrossmullen]

Feature Request

• [x] I’ve read and understood the Contributing guidelines and have done my best effort to follow them.
• [x] I’ve read and agree to the Code of Conduct.
• [x] I’ve searched for any related issues and avoided creating a duplicate issue.
• [x] I've searched the community forums to check for related issues or feature requests

Is this feature request relating to an existing component? Please describe.

• All components

Do you have a suggestion for a new component?

All components require the addition of a matrix in their readme describing the support against browsers and assistive technologies. This matrix should describe the expected behaviour of the component and how this actually compares against the browser and AT combinations.

A component may accurately convey it's behaviour in JAWS and Chrome, but not in NVDA and Chrome. Existing foundational components in the design system will probably have universal support but as components become complex using aria attributes this is where patchy support will be identified.

This matrix helps identify gaps in browser and assistive technologies.

Example

	JAWS	NVDA	VoiceOver
Chrome	x	x	x
Edge (Chromium)	x	x	x
FireFox	x	x	x

Additional context

This support matrix is in addition to WCAG 2.1 AA tests.

[mrrossmullen]

Combine the support matrix with the accessibility acceptance criteria from the UK Government and the BBC which

describe the necessary behaviours that any control needs to meet to be usable by assistive technologies