Docs: Improve CSS renderer pages. (#25463)

* Docs: Improve CSS renderer pages.

* Docs: Clean up.

* Docs: More clean up.

docs/examples/en/renderers/CSS2DRenderer.html

@@ -10,7 +10,8 @@
 		<h1>[name]</h1>
 
 		<p class="desc">[name] is a simplified version of [page:CSS3DRenderer]. The only transformation that is supported is translation.<br /><br />
-			The renderer is very useful if you want to combine HTML based labels with 3D objects. Here too, the respective DOM elements are wrapped into an instance of `CSS2DObject` and added to the scene graph.<br />
+			The renderer is very useful if you want to combine HTML based labels with 3D objects. Here too, the respective DOM elements are wrapped into an instance of `CSS2DObject` and added to the scene graph.<br /><br />
+			`[name]` only supports 100% browser and display zoom.
 		</p>
 
 		<h2>Examples</h2>

docs/examples/en/renderers/CSS3DRenderer.html

@@ -18,6 +18,7 @@
 			<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>`[name]` only supports 100% browser and display zoom.</li>
 			</ul>
 			So `[name]` is just focused on ordinary DOM elements. These elements are wrapped into special objects (`CSS3DObject` or `CSS3DSprite`) and then added to the scene graph.
 		</p>

docs/examples/zh/renderers/CSS2DRenderer.html

@@ -10,7 +10,8 @@
 		<h1>CSS 2D渲染器（[name]）</h1>
 
 		<p class="desc">[name]是[page:CSS3DRenderer]（CSS 3D渲染器）的简化版本，唯一支持的变换是位移。<br /><br />
-			如果你希望将三维物体和基于HTML的标签相结合，则这一渲染器将十分有用。在这里，各个DOM元素也被包含到一个*CSS2DObject*实例中，并被添加到场景图中。<br />
+			如果你希望将三维物体和基于HTML的标签相结合，则这一渲染器将十分有用。在这里，各个DOM元素也被包含到一个*CSS2DObject*实例中，并被添加到场景图中。<br /><br />
+			`[name]` only supports 100% browser and display zoom.
 		</p>
 
 		<h2>例子</h2>

docs/examples/zh/renderers/CSS3DRenderer.html

@@ -19,6 +19,7 @@
 			<ul>
 				<li>它不可能使用*three.js*中的材质系统。</li>
 				<li>同时也不可能使用几何体。</li>
+				<li>`[name]` only supports 100% browser and display zoom.</li>
 			</ul>
 			因此，[name]仅仅关注普通的DOM元素，这些元素被包含到了特殊的对象中（*CSS3DObject*或者*CSS3DSprite*），然后被加入到场景图中。
 		</p>