For content that appears in both games, on both Wiki's page there will be notification on the top of the page that allows the user easy access to the other Wiki's page; for example, on the Hollow Knight Wiki, there'll be such a notification on Hornet's page that will link to the Silksong Wiki's Hornet page, and vice versa.
Where relevant, both Wikis will link to the other Wikis just like when we interlink on the same Wiki between pages, from a user point of view, this will be no different. From an editor point of view, we'll be using full URLs instead of the usual code, but this is trivial.
Should the need arise, we can make a separate Lore wiki for HK where both games' lore is present and easily searchable.
The Wiki Discord will remain the same for both Wikis: https://discord.gg/DuVNd4s
The Silksong Wiki's URL is https://silksong.fandom.com/ and I will be copying over the CSS, JS, templates and other relevant stuff to it in the coming week(s), setting up a new theme etc. For the time being, please refrain from creating new pages on it, and instead collate all Silksong-related info on this page: https://hollowknight.fandom.com/wiki/Silksong
If you have any questions, please do not hesitate to ask me.