docs/zh_CN: add management-style.rst in Chinese

It's a enjoy to read and translate this doc, although I cann't find the
original author from git history -- it came with 2.6.12-rc2, the initial
git repo.
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>