Update Frustum.html

added minor improvement to docs. Also, the name of the Frustum's method should reflect the explanation and be changed to intersectsObjectBoundingSphere(...)

docs/api/math/Frustum.html

@@ -43,7 +43,7 @@
 
 		<h3>.intersectsObject( [page:Object3D object] ) [page:Boolean]</h3>
 		<div>
-		Checks whether the object is inside the Frustum.
+		Checks whether the object's bounding sphere is intersecting the Frustum.
 		</div>
 
 		<h3>.clone() [page:Frustum]</h3>