* feature(spinners): slow down spinners when prefers-reduced-motion

* docs(spinners): add reduced motion callout and mention slowing down in accessibility page

* Update spinners.md

* docs(accessibility): rewording

Co-authored-by: XhmikosR <xhmikosr@gmail.com>
Co-authored-by: Patrick H. Lauke <redux@splintered.co.uk>