chore: Correct minor capitalization mistake (#534)

Author: rschristian

index.html

@@ -640,7 +640,7 @@ <h2 id="docconformance">
                 <p>
                   Roles:
                   <a href="#index-aria-button">`button`</a>
-                  or <a href="#index-aria-link">`link`</a>. (<code><a href="#index-aria-generic">generic</a></code> is also allowed, but SHOULD NOT BE USED.)
+                  or <a href="#index-aria-link">`link`</a>. (<code><a href="#index-aria-generic">generic</a></code> is also allowed, but SHOULD NOT be used.)
                 </p>
                 <p><a>Naming Prohibited</a></p>
                 <p>