Runs on Folia

• New: Folia support, in the same jar as Spigot and Paper. Each player's view and seated page runs on that player's own region thread, and everything else on the global one.
• New: a startup banner in the console. It shows the version, links to our Discord, the docs and Studio, and a short report of what started, ending with how long it took and how many warnings there were. When a newer version is on SpigotMC, the banner says so.