Changed "an" to "and" in graph3D docs

docs/graph3d/index.html

@@ -184,7 +184,7 @@
   <p>
     The class name of the Graph3d is <code>vis.Graph3d</code>.
     When constructing a Graph3d, an HTML DOM container must be provided to attach
-    the graph to. Optionally, data an options can be provided.
+    the graph to. Optionally, data and options can be provided.
     Data is a vis <code>DataSet</code> or an <code>Array</code>, described in
     section <a href="#Data_Format">Data Format</a>.
     Options is a name-value map in the JSON format. The available options