doc/zh_CN: add mips features.rst translation

This patch translates Documentation/mips/features.rst into Chinese.
Signed-off-by: Yanteng Si <siyanteng@loongson.cn>
Reviewed-by: Alex Shi <alex.shi@linux.alibaba.com>
Link: https://lore.kernel.org/r/20210112115259.217944-3-siyanteng@loongson.cnSigned-off-by: Jonathan Corbet <corbet@lwn.net>

Documentation/translations/zh_CN/mips/features.rst

+.. SPDX-License-Identifier: GPL-2.0
+
+.. include:: ../disclaimer-zh_CN.rst
+
+:Original: :ref:`Documentation/mips/features.rst <features>`
+:Translator: Yanteng Si <siyanteng@loongson.cn>
+
+.. _cn_features:
+
+.. kernel-feat:: $srctree/Documentation/features mips