Tiny update - May 13th — Baba Is You Steam update #120099

I meant to wait a bit longer and have a larger update done, but I wanted to get one of these changes out faster so here we are. - Added guest credits to "Across" (level in the ??? area.) Apologies to Corey Martin for missing that when adding the level. - A relatively large underlying code rework to prepare for certain even larger future changes. This will break mods, but might cause other issues as well. Apologies for the trouble; once I get this and that later additional change done things should* be more stable. * Hopefully