add config_proxy2 for wsl2

[xiayh17]

Hi
Thank you for developing the zsh-proxy plugin, it is very convenient and easy to use.
I'm a User of Windows Subsystem for Linux. Recently I was planning to move to WSL2, but found the following problems of WSL2.

WSL 2 has a virtualized ethernet adapter with its own unique IP address. So WSL will have a different IP address every time it starts.
Microsoft's official reference document.

In other words, setting up a proxy for WSL cannot use 127.0.0.1 or other fixed network segments. Obtaining this dynamic IP automatically has become a key problem.
config_proxy2 option was added to solve this problem.

Thanks again！
Sincerely

[SukkaW]

Add a config_proxy2 might be duplicated. What about asking environment or detect WSL2 directly during config_proxy?

For example:

[environment]  {Default is "Default"}
([D]efault, WSL[2]): 

[xiayh17]

I found a way to judge the WSL version.
But after the WSL environment is detected, I need the user to diagnose whether the WSL version is 2.
Because I haven't found an infallible method to determine whether WSL is version 2.

For WSL2 users, this script has a hidden danger. LAN IP acquisition depends entirely on the resolv.conf file

❯ cat /etc/resolv.conf
# This file was automatically generated by WSL. To stop automatic generation of this file, add the following entry to /etc/wsl.conf:
# [network]
# generateResolvConf = false
nameserver 172.30.240.1

When resolv.conf be set as stop automatically generated. The script will not work.

[Ziy1-Tan]

This feature is what we need, are there any plans to restart it?

[xiayh17]

This feature is what we need, are there any plans to restart it?

It appears that further modifications are necessary for the current version.