Docs: Improve limitations section of CSS3DRenderer

docs/examples/renderers/CSS3DRenderer.html

@@ -16,6 +16,7 @@
 			<ul>
 				<li>It's not possible to use the material system of *three.js*.</li>
 				<li>It's also not possible to use geometries.</li>
+				<li>Only [page:PerspectiveCamera] is supported right now.</li>
 			</ul>
 			Instead, you have to build your scene with ordinary DOM elements. The elements are wrapped into special objects (*CSS3DObject* or *CSS3DSprite*) and then added to the scene graph.
 		</div>