docs/zh_CN: core-api: Add watch_queue Chinese translation

Translate core-api/watch_queue.rst into Chinese.

Last English version used:
commit f5461124 ("Documentation: move watch_queue to core-api").
Signed-off-by: Binbin Zhou <zhoubinbin@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Link: https://lore.kernel.org/r/20220710133604.31382-1-zhoubinbin@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/translations/zh_CN/core-api/index.rst

@@ -28,6 +28,7 @@
    printk-basics
    printk-formats
    workqueue
+   watch_queue
    symbol-namespaces
 
 数据结构和低级实用程序