Add doc (17807)

Signed-off-by: Nester.zhou <ester.zhou@huawei.com>

en/release-notes/changelogs/OpenHarmony_3.2.12.2/changelog-notification.md

+# Notification Subsystem Changelog
+
+Compared with OpenHarmony 3.2 Release, OpenHarmony 3.2.12.2 provides more detailed error code information for the APIs of the notification subsystem.
+
+## cl.notification.1 Added and Optimized API Error Code Description
+
+The error code description and all error codes that may be returned by the APIs are commented out. This helps developers control the error process more accurately.
+
+**Change Impact**
+
+The external declaration of the JS APIs of API version 9 is affected, but the API functionalities are not affected. You can determine whether to adapt to the JS APIs.
+
+**Key API/Component Changes**
+
+The comments of the following modules are updated. For details, see the corresponding external API declaration and API development guide.
+
+| Module                       | Major Change                                              |
+| --------------------------- | ------------------------------------------------------------ |
+| @ohos.commonEventManager    | Added the description of error codes 801, 1500007, and 1500008.                   |
+| @ohos.notificationManager   | Added the description of error codes 201, 202, 1600001, 1600002, 1600003, 1600004, 1600005, 1600007, 1600008, 1600009, 1600010, and 17700001, and adjusted the description of error code 401.|
+| @ohos.notificationSubscribe | Added the description of error codes 201, 202, 1600001, 1600002, 1600003, 1600007, 1600008, and 17700001, and adjusted the description of error code 401.|