docs/zh_CN: Improve zh_CN/process/4.Coding.rst

Improve language and grammar of zh_CN/process/4.Coding.rst

Signed-off-by: Wu XiangCheng <bobwxc@email.cn>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/66d6ec99bdd0f41c91951d33eb0fa7c4748019a4.1614920267.git.bobwxc@email.cn


Signed-off-by: Jonathan Corbet <corbet@lwn.net>