That sounds like a lot of information. Not just about the free software movement, but also tutorials? And if I understand correctly, you want some kind of list of libre apps and programs?
I think there should be a website that answers the most common questions and explains common misconceptions. So that we could always send somebody a link to a specific answer when they appear to be confused about the movement. But I'm not sure about the other stuff, since it seems like a big project.
It should have content about other non-free operating systems and how to make them a little more free
It could just list free software replacements for common proprietary software. For example: use Firefox instead of Chrome
or use Signal instead of Whatsapp
. This could be sorted by level of difficulty. Replacing Windows/MacOS with GNU/Linux could be one of the last things on that list, because it's probably one of the hardest. But that's probably not the type of content that's right for a wiki.
I would like there to be some website about GNU/Linux phones, since it's hard to find information about them on the internet. But there aren't many people with experience in this area, so keeping that stuff up to date would be difficult.
The software or service
Libre Planet's wiki seems to be running on MediaWiki.
the domain
Maybe:
freesoftware.wiki
libresoftware.wiki