The main page has changed so markedly since I last touched it that I don't want to learn how to do anything to it. I hope one of you younger folk can add that section.
We have a Project: page on which we can list good candidates (already half a dozen listed) and vote on which ones should feature: Civilization Wiki:Featured articles. Ideally change once a month or even once a week. Use Category:Featured articles for the selected articles. Civilization Wiki:Featured articles/system can be a guide. Fandom used to have a standard system but I think it was abandoned because of difficulties relating to mobile viewers.