Final call: new rule, HTML page language subtag matches default language

Hey folks,
This rule can be used to test that the language of the page is correctly
identified using the lang attribute of the HTML element. It was one of the
more obvious gaps in the ACT ruleset, that we have rules that test the page
language is defined, but not that it is actually correct. The final call
ends on September 2nd. If you have any feedback, leave a review on the pull
request:

https://github.com/act-rules/act-rules.github.io/pull/1334

-- 
*Wilco Fiers*
Axe for Web product owner - Co-facilitator WCAG-ACT - Chair ACT-R