Call for review: aria-hidden not focusable, add hidden svg in link example

Hey folks,
Per an AGWG request, I've added an example of an aria-hidden element inside
a link (rather than the reverse, which would fail).

This review lasts 7 days, ending on Monday October 17th. If you have any
comments, please leave a review on the pull request:
https://github.com/act-rules/act-rules.github.io/pull/1933

-- 
*Wilco Fiers*
Axe-core & Axe-linter product owner - WCAG 3 Project Manager - Facilitator
ACT Task Force