[charter] Mention MAUR and FAST documents explicitly (#19)

Addresses feedback received during accessibility review of the draft charter.

charters/charter-2019.html

@@ -187,7 +187,13 @@ <h2>Scope</h2>
             development and use of W3C standards within global media specifications.</li>
           <li>Ensuring issues of accessibility, device independence,
           internationalization, performance, privacy, and security are given
-          equal consideration in all discussions and outcomes.</li>
+          equal consideration in all discussions and outcomes. This includes
+          consideration of accessibility requirements in the latest versions of
+          the <a href="https://www.w3.org/TR/media-accessibility-reqs/">Media
+          Accessibility User Requirements</a> and
+          <a href="https://w3c.github.io/apa/fast/">Framework for Accessible
+          Specification of Technologies (FAST)</a> documents, and feedback from
+          the Interest Group on these specifications.</li>
         </ul>
 
         <p>