The Arch Wiki is the gold standard of wikis 🙂
Note that it is replacing the old URL https://jlk.fjfi.cvut.cz/arch/manpages/
This is well made.The web page gives a nice overview, and is easy to search. I see that Jakub Klinkovský stands behind many of the commits to archmanweb. Nicely done!
wiki.archlinux is my first choice for linux related stuff. Now man.archlinux for man pages