Add the function of exporting rules as a pac file

[goddade]

ZeroOmega version / ZeroOmega 版本

Browser version & OS version / 浏览器名称、版本及操作系统版本

Problem description / 问题描述

(Please provide as much detail as possible. We recommend the following format.) (请尽可能多提供一些细节。我们推荐使用下面的格式。)

Steps to reproduce issue / 重现错误所需步骤

(What did you do? / 你做了什么？)

1. 2. 3.

Expected behavior / 期望发生的情况

Actual (or suggested) behavior / 实际发生的情况（或建议修改后的行为）

[zero-top]

[goddade]

Thank you