Broken accessibility link in readme

[swashbuck]

adapt_framework/README.md

Line 20 in 44ea801

+ [Meets WAI AA accessibility standards](https://github.com/adaptlearning/adapt_framework/wiki/Accessibility)

The link https://github.com/adaptlearning/adapt_framework/wiki/Accessibility does not exist yet.

Should this link to the new guide that will presumably be created in #3379 @kirsty-hames @oliverfoster ?

[kirsty-hames]

Looks like that link was added 6 years ago and not populated. Whilst we do need to put some guidance together as per #3379 I hadn't thought what form this would take.

Perhaps as a starter, we could create that Accessibility page and populate with some headings for areas we want to cover? We could focus on any v5 changes to build on from the Accessibility v3 to v4 wiki? This page gives a good overview to accessibility in Adapt but some config/syntax will be outdated now.