chore: cite HTML-AAM spec for section→region role mapping

Author: johanrd

tests/lib/rules/template-no-nested-landmark.js

@@ -45,7 +45,7 @@ ruleTester.run('template-no-nested-landmark', rule, {
 
     // `<section>` only gets the `region` landmark role when it has an accessible name
     // (aria-label/aria-labelledby/title). Without one it has the generic role — see
-    // https://developer.mozilla.org/en-US/docs/Web/Accessibility/ARIA/Reference/Roles/region_role.
+    // https://www.w3.org/TR/html-aam-1.0/#el-section
     // This rule does not inspect accessible names, so unnamed sections are excluded.
     '<template><section><section>Content</section></section></template>',
     // `role="region"` is the landmark role a named `<section>` gets. Nesting it is