update zh-cn/application-dev/ability/stage-formextension.md.

Signed-off-by: N@ge-yafang <geyafang@huawei.com>
Signed-off-by: N葛亚芳 <geyafang@huawei.com>

zh-cn/application-dev/ability/stage-formextension.md

@@ -415,4 +415,5 @@ onUpdate(formId) {
 ## 相关实例
 
 针对Stage模型卡片提供方的开发，有以下相关实例可供参考：
-- [`FormExtAbility`：Stage模型卡片（eTS）（API9）](https://gitee.com/openharmony/applications_app_samples/tree/master/ability/FormExtAbility)
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+- [`FormExtAbility`：Stage模型卡片（eTS）（API9）](https://gitee.com/openharmony/applications_app_samples/tree/master/ability/FormExtAbility)
+- [`GalleryForm`：图库卡片（eTS）（API9）](https://gitee.com/openharmony/applications_app_samples/tree/master/ability/GalleryForm)
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