Add LoadGeneralRewardResponse notes

Mapped this out while investigating an issue that turned out to be
unrelated, may as well check in my findings.

src/idz/handler/loadGeneralReward.ts

@@ -1,11 +1,12 @@
 import { LoadGeneralRewardRequest } from "../request/loadGeneralReward";
 import { GenericResponse } from "../response/generic";
+import { LoadGeneralRewardResponse } from "../response/loadGeneralReward";
 import { World } from "../world";
 
 export function loadGeneralReward(
   w: World,
   req: LoadGeneralRewardRequest
-): GenericResponse {
+): LoadGeneralRewardResponse | GenericResponse {
   // A non-generic response is also accepted, but why bother
   return { type: "generic_res" };
 }