Update PerspectiveCamera.html (#28040)

docs/api/zh/cameras/PerspectiveCamera.html

@@ -82,7 +82,7 @@
 
 		<h3>[property:Boolean isPerspectiveCamera]</h3>
 		<p>
-			Read-only flag to check if a given object is of type [name].
+			只读属性，用于检查给定的对象是否为 [name]。
 		</p>