Update for new behavior

docs/api/geometries/ParametricGeometry.html

@@ -47,7 +47,7 @@
 
 		<h3>[name]([param:Function func], [param:Integer slices], [param:Integer stacks])</h3>
 		<p>
-		func — A function that takes in a [page:Float u] and [page:Float v] value each between 0 and 1 and returns a [page:Vector3]<br />
+		func — A function that takes in a [page:Float u] and [page:Float v] value each between 0 and 1 and modifies a third [page:Vector3] argument<br />
 		slices — The count of slices to use for the parametric function <br />
 		stacks — The count of stacks to use for the parametric function
 		</p>