I like this title format for example: [Wiki] Ground based generators - Groundgen with the [Wiki] at the beginning of the title, and the topic should have the wiki tag to find it more easily.
Other than that, just start? If a wiki gets more content perhaps think a bit about formatting and organization then.
You can make a comment a wiki if you are a regular or above IIRC by clicking the three dots next to the reply button, then the wrench that appears in place of the three dots, and then “Make Wiki.”
I don’t know, one way to do it would be to reserve a few, say 5 or however many you like, top comments to convert to wiki comments and don’t close the topic but make it not discussion based like in my examples above. Then if a new comment adds new information add it to the wiki comments.
That is a low threshold way for people to contribute, not needing to figure out how to edit a wiki, where the new info should go, or if it should be added at all, and have someone else think about that. The top comment can state the moderation rules, say any comment that doesn’t add info gets removed, or all comments get removed after the relevant info is added to the wiki comments.
If a wiki and category match well, maybe pin it the moment it gets created so there is more motivation to add content to it.