Docs: Clean up.

docs/api/en/extras/curves/CatmullRomCurve3.html

@@ -72,6 +72,8 @@
 		<h2>Methods</h2>
 		<p>See the base [page:Curve] class for common methods.</p>
 
+		<h2>Source</h2>
+
 		<p>
 			[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]
 		</p>

docs/api/zh/extras/curves/CatmullRomCurve3.html

@@ -73,6 +73,8 @@
 		<h2>方法</h2>
 		<p>共有方法请参见其基类[page:Curve]。</p>
 
+		<h2>源代码</h2>
+
 		<p>
 			[link:https://github.com/mrdoob/three.js/blob/master/src/[path].js src/[path].js]
 		</p>