This patch translates Documentation/core-api/index.rst into Chinese.
add Documentation/translations/zh_CN/core-api/irq/* to zh_CN/core-api/index.rst.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Wu XiangCheng <bobwxc@email.cn>
Link: https://lore.kernel.org/r/d246fcd092111338d64f6b678dda2cd67fcb3f4a.1618568135.git.siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>