!17594 modify docs of prop

Merge pull request !17594 from yfwang6/prop

zh-cn/application-dev/quick-start/arkts-prop.md

@@ -350,18 +350,13 @@ struct MainProgram {
       }
 
       Row() {
-        Column(       
+        Column()
         // customCounter必须从父组件初始化，因为MyComponent的customCounter成员变量缺少本地初始化；此处，customCounter2可以不做初始化。
         MyComponent({ customCounter: this.mainCounter })
         // customCounter2也可以从父组件初始化，父组件初始化的值会覆盖子组件customCounter2的本地初始化的值
         MyComponent({ customCounter: this.mainCounter, customCounter2: this.mainCounter })
       }.width('40%')
     }
-
-      Row() {
-        Text('').width(480).height(10)
-      }
-    }
   }
 }
 ```