Re-add ECS_PAIR_* to typings (#241)

* Add ECS_PAIR_* functions to typings

* Return simple numbers

jecs.d.ts

@@ -165,7 +165,7 @@ export class World {
 	 * @param component The component definition (could be a Pair or Entity).
 	 * @param value The value to store with that component.
 	 */
-	set<T>(entity: Entity, component: Id<T>, value: T): void;
+	set<E extends Id<unknown>>(entity: Entity, component: E, value: InferComponent<E>): void;
 
 	/**
 	 * Cleans up the world by removing empty archetypes and rebuilding the archetype collections.
@@ -288,6 +288,9 @@ export function pair_first<P, O>(world: World, p: Pair<P, O>): Entity<P>;
  */
 export function pair_second<P, O>(world: World, p: Pair<P, O>): Entity<O>;
 
+export function ECS_PAIR_FIRST(pair: Pair): number;
+export function ECS_PAIR_SECOND(pair: Pair): number;
+
 type StatefulHook = Entity<<T>(e: Entity<T>, id: Id<T>, data: T) => void> & {
 	readonly __nominal_StatefulHook: unique symbol,
 }