Fedwiki
Discord
I don't know of any either! The closest I know of is ward's Fedwiki: but i plan on making one (probably more related to <#1038983225348993184> than this channel, which i am trying hard not to derail lol)
Looking forward to your work in this space! I do know about Fedwiki but only as a spectator. I tried to convince a few colleagues to set up a network of Fedwikis in our research domain, but nobody was keen on becoming a sysadmin to run their own Wiki instance.