Call for review: add 1.1.1 as secondary to Decorative element not exposed

Hey folks,
This PR is adding 1.1.1 as a secondary requirement to the Element marked as
decorative is not exposed rule. This rule clearly applies to images, even
if it applies to more things than images. Therefore it is perfectly
consistent for testers to sometimes fail 1.1.1 when this rule fails:
https://github.com/act-rules/act-rules.github.io/pull/2224

If you have any concerns or questions, please respond to this PR before
January 27th.

Kind regards

-- 
*Wilco Fiers*
Principal product owner - W3C AC Rep - Facilitator ACT Task Force