a11y upgrades - refer to van11y

[joesnellpdx]

Verify a11y implementation and guidance is correct on components

Use Van11y as a resource to do the following (if another resource feels appropriate, please include):

1. analyze any enhancements we can / should make to our existing components
2. add any new components

From findings, create new issues / tasks to move this forward.

Van11y: https://van11y.net/

(also, run through a11y testing suites - i.e. siteimprove, axe)