Chezzo ran a wiki that was used by the game for some time at:

http://cddawiki.chezzo.com/cdda_wiki/index.php

A lot of useful information, like about martial arts and such, is on there. Unfortunately, that domain apparently went down about two months ago.

A (fairly-recent) copy of the wiki, archived in late March 2024, can apparently be viewed at:

https://web.archive.org/web/20240324103752id_/https://cddawiki.chezzo.com/cdda_wiki/index.php/Main_Page

It looks like archive.org also dumped a several-months-older copy of the site, from August 2023, with MediaWiki-scraper:

https://archive.org/details/wiki-cddawikichezzocom_cdda_wiki

I’d guess that this is sufficient to bring the Wiki back to life if someone with a MediaWiki setup wants to do so.