Add the NixOS unofficial wiki to unofficial sources (https://nixos.wiki/wiki/)

[ahydronous]

Introduce your stance
The unofficial wiki is a great (if sometimes outdated) source for configuring NixOS. It often has helpful code blurbs.

Describe the issue
https://nixos.wiki/wiki is currently not in the unofficial sources.

Page links
https://nixos.org/community/

• I already created a Pull Request

[mschwaig]

The unofficial wiki has been superseded by the official one.

As far as I am aware all of the content has been migrated, but the person running the unofficial wiki is not responsive to cooperating with that effort that effort. So it would be kind of counter-productive to link the unofficial wiki anywhere.

You can read more about that at NixOS/foundation#113 and https://wiki.nixos.org/wiki/NixOS_Wiki:History.