docs/zh_CN: Update and fix a couple of typos

Update to the original README.rst and fix some typos.

Signed-off-by: Shile Zhang <shile.zhang@linux.alibaba.com>
Reviewed-by: Alex Shi <alexs@kernel.org>
Link: https://lore.kernel.org/r/20211230025702.186158-1-shile.zhang@linux.alibaba.com
Signed-off-by: Jonathan Corbet <corbet@lwn.net>