I want to build out a knowledge base and collect information for everyone to share and contribute.
What is a good browser, self-hosted version of a wiki? I would like to change the design and maybe built out own functionality, and also start somewhere so I don't have to build everything from scratch.
There has long since been server versions, and recently they released a new and improved service version which takes aim at your needs.
From my experience it's more often not the tools but the content.
For comments you could use https://giscus.app which integrates very nicely with GitHub.
Doing so you have *no* setup costs.
I'm aware that this is not exactly *self hosted* -- but it has the advantage that you have no upfront cost. And most of the static site generators are just that, you could host the output on any 5$ web server.