docs/zh_CN: correct the disclaimer file

The original disclaimer remind people to get help from the specific
Chinese doc maintainers. But there are lots docs has no 'specific
maintainers' and some of maintainer doesn't updated the docs for years.
So replace the Chinese word maintainer with translator. That's more
precise for these people's role of their docs.

Signed-off-by: Alex Shi <alex.shi@linux.alibaba.com>
Cc: Harry Wei <harryxiyou@gmail.com>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Jonathan Corbet <corbet@lwn.net>