add note about the namespace change

Author: sandhawke

ns/index.html

@@ -453,6 +453,9 @@ <h2 id="w3c-document-13-april-2018"><abbr title="World Wide Web Consortium">W3C<
       <dt><code>vcard</code>:</dt>
       <dd><code>http://www.w3.org/2006/vcard/ns#</code></dd>
     </dl>
+
+    <p><em>Note: The <b>as</b> namespace was changed from http to https in the JSON-LD contenxt document with version 1.10, which became active at 2018-04-16T00:28:23Z, following community discussion. This is not viewed as a normative change to the ActivityStreams specifications, because they specify the syntax in terms of JSON-LD not RDF triples. For more details see <a href="https://github.com/w3c/activitystreams/issues/495">issue-495</a></p>
+    
   </section>
 
   <section property="bibo:hasPart" resource="#class-definitions" typeof="bibo:Chapter" id="class-definitions">