feat: theme for ggj2025

Author: AlexStormwood

src/content/docs/global-game-jam/ggj2025.md

@@ -4,9 +4,9 @@ description: Themes, diversifiers, and other info about GGJ2025.
 ---
 
 ## Main Theme
-### (Not Yet Released)
+### Bubble
 
-(Content needed)
+[https://www.youtube.com/watch?v=wJhQ9Z4MCM4](https://www.youtube.com/watch?v=wJhQ9Z4MCM4)
 
 ## Headline Partners
 ### Peaceformers (G4C University Student Challenge)
@@ -206,4 +206,4 @@ Contained in your game
 
 
 ### Strange as folk
-Your game has a folk horror theme.
+Your game has a folk horror theme.