Call for review: Add "funding" to acknowledgments

Hey folks,
This PR adds a funding flag to the frontmatter of all of our ACT rules. At
this moment, all rules were to some extent written through the EU funded
WAI-Tools project. But there are rules in development that aren't. This
flag lets us differentiate.

If you have any concerns, please leave a review on the pull request by
September 14th:
https://github.com/act-rules/act-rules.github.io/pull/1694

Kind regards,

-- 
*Wilco Fiers*
Axe-core product owner - Facilitator ACT Task Force - Co-chair ACT-Rules