refactor: split WorldEvent into EntityEvent and RelEvent

src/index.ts

@@ -11,6 +11,8 @@ export { makeEntity, entityIndex, entityGeneration } from "./entity";
 export { SparseSet } from "./storage/sparse-set";
 export type {
   WorldEvent,
+  EntityEvent,
+  RelEvent,
   QueryUpdate,
   RelationshipUpdate,
 } from "./observable/events";