Update QuadCallback to use array of Quads instead of just a single quad

The toRDF() algorithm hasn't been updated yet to call the callback.

This addresses #200.

Author: lanthaler

spec/latest/json-ld-api/index.html

@@ -665,8 +665,8 @@ <h3>JsonLdProcessor</h3>
           <dd>The JSON-LD object or array of JSON-LD objects to convert to RDF or a <a>IRI</a>
             referencing the JSON-LD document to convert to RDF.</dd>
           <dt>QuadCallback callback</dt>
-          <dd>A callback that is called when a <ldtref>Quad</ldtref> is created from processing
-            the given <code>input</code>.
+          <dd>A callback that is called when the input <code>input</code> has been converted
+            to <ldtref title="Quad">Quads</ldtref>.
           </dd>
           <dt>optional JsonLdOptions? options</dt>
           <dd>A set of options that MAY affect the conversion to RDF such as, e.g.,
@@ -777,8 +777,8 @@ <h3>QuadCallback</h3>
              and the details will be contained within the <code>error</code>
              object.
            </dd>
-           <dt>Quad quad</dt>
-           <dd>If there is no error, the quad that was generated.</dd>
+           <dt>Quad[] quads</dt>
+           <dd>If there is no error, the quads that have been generated.</dd>
         </dl>
         </dd>
       </dl>