Update index.html

Co-Authored-By: David I. Lehn <[email protected]>

Author: gkellogg

index.html

@@ -1569,7 +1569,7 @@ <h3>Algorithm</h3>
               error has been detected and processing is aborted.</li>
             <li id="ctd-invalid-type">Otherwise, if the expanded <var>type</var> is
               neither <code>@id</code>, nor <code>@json</code>,
-              not <code>@none</code>,
+              nor <code>@none</code>,
               nor <code>@vocab</code>, 
               nor an <a>IRI</a>,
               an <a data-link-for="JsonLdErrorCode">invalid type mapping</a>