Make key name more explicit.

src/lib/situations.ts

@@ -23,7 +23,7 @@ export interface EntitySituationWithoutId {
 }
 
 export interface Situation {
-  [key: string]: { [id: string]: EntitySituationWithoutId }
+  [entityKeyPlural: string]: { [id: string]: EntitySituationWithoutId }
 }
 
 export type SituationWithAxes = Situation & {