Hex already covered some important points, but I'll give my view on it too.
Discord (https://discord.gg/momentummod) is great for live community and quick-info interactions. I agree that the Q&As might be getting a bit repetitive as we get fresh faces joining the Discord, but the team has plans to mitigate that by just linking the answers to people asking them, and skipping over the questions. I fully agree that Discord sucks as an information base. I do not plan on having it replace in-depth, organized community interactions (this forum) or readily-available static information that can be searched and properly linked in conversations (the docs website).
These forums (https://forum.momentum-mod.org), as mentioned above, are meant to cover the structured, in-depth conversations people can have about a topic. Discord really dropped the ball with threads in my opinion, so having this is great. Still community oriented, and also hooked into our Discord as to promote discussions better. While we have some static information, it's already pretty outdated, and requires manual updating to reflect it. For example, the FAQ thread is already pretty out of date.
The main website (https://momentum-mod.org) is fantastic for absolutely static, Momentum Mod brand information. Updating the frontend isn't hard, it's literally a click of a button after it gets merged in, but the front page is currently just a static site, meant to show people at a glance what Momentum Mod is about. It's basically a more in-depth Steam Store page, as we have full creative control over the page layout and contents. People can go to this page to see more information about this finagled "Momentum Mod" their friends keep talking about. But it doesn't have any search options, and only is meant to act as a hub for linking people to things so they can find out more about us and our community.
Which brings us to: the docs website (https://docs.momentum-mod.org). It's meant to be static information about Momentum Mod, its supported modes, its convars, its concommands, its entities, its shaders, various guides for various Momentum Mod things, and more.
So, no, it's not, it's really just limited to being about Momentum, and not necessarily every single part of the content we support. While we don't want offhand information about random map trivia or something, we absolutely do want history and information about our game modes, linking to resources, including our game to be able to apply what you've read. If people even are reading something (more on that in a bit), it has to be worth their time and not be pointless faff. Is map trivia really about Momentum? Even if the maps are available in their base games as well?
tam Github pull requests make it a bit harder to edit than a wiki imo.
You can edit the docs site completely from the web interface from GitHub, and more serious changes should be done on a local version of the docs site anyways. Making it trivial to edit = way more potential for off topic, spam, etc stuff that, as Hex mentioned, is something we don't really want to add to the list. It being a static website as well means that we get more control over the look-and-feel of the pages (Jekyll is very powerful!), including proper search. Have you tried MediaWiki search? There's a reason I shudder every time I have to use the Valve Dev Wiki... 😬
But it brings me to my last, but most important point. We already try to require people to read the FAQ to get access to the server. We could have another custom Discord Bot that links people helpful information, or we could even have a little exam to make sure they read it. But that's the problem:
People don't like to read things!!
Be it in Discord, on a website, on a wiki, on the docs site, people are so lazy to read information right in front of them that it's just frustrating to even think about opening yet another information site that duplicates known information, and that's if people even bother to read it or check it out.
So what will a wiki really solve over our docs site? If we host it, it's another thing to add to the monthly bill, if we don't, who knows how long that site will hold it or what they do with people's accounts etc. If it's on GitHub, it's basically the same as the docs site. It's another thing to moderate, even if we take a more hands-off approach, whereas PRs for the docs repository are extremely straight forward to be able to discuss more. If something was closed (referring to your asterisk imgur link), that means it was likely poor quality to begin with and needs more work. Something we wouldn't want slapped on an official wiki then need to go and correct manually after the fact.
riotbz If I tried to play conc or ahop I would have no idea where to start, or what the differences are compared to other gamemodes (beyond putting a message in the discord black hole).
Did you see our Learn section stuff we have planned? We plan to go over everything in game for this. It would be a massive UX failure in our game to tell people to go to a random Discord server or wiki website to figure it all out.