infer room format

src/game.rs

@@ -386,6 +386,11 @@ impl Game {
     pub fn version(&self) -> Version {
         self.version.unwrap_or(Version { major: 1, minor: 0 })
     }
+
+    /// older bitsy games do not specify a room format, but we can infer 0
+    pub fn room_format(&self) -> RoomFormat {
+        self.room_format.unwrap_or(RoomFormat::Contiguous)
+    }
 }
 
 #[cfg(test)]