feat: add other impl

Author: MichaelVerdon

packages/firestore/lib/modular/snapshot.d.ts

@@ -237,3 +237,18 @@ export declare function queryEqual<AppModelType, DbModelType extends DocumentDat
  * @param onSync
  */
 export declare function onSnapshotsInSync(firestore: Firestore, onSync: () => void): Unsubscribe;
+
+/**
+ * /**
+ * Attaches a listener for a snapshots-in-sync event.
+ * The snapshots-in-sync event indicates that all listeners affected by a given change have fired, even if
+ * a single server-generated change affects multiple listeners.
+ *
+ * @param firestore
+ * @param onSync
+ */
+export declare function onSnapshotsInSync(firestore: Firestore, observer: {
+  next?: (value: void) => void;
+  error?: (error: FirestoreError) => void;
+  complete?: () => void;
+}): Unsubscribe;