feat: use tsnapi for exports snapshoting

__snapshots__/tsnapi/index.snapshot.d.ts

@@ -0,0 +1,5 @@
+/**
+ * Generated by tsnapi — public API snapshot of `pkg-placeholder` */
+// Variables
+export declare const one: number;
+export declare const two: number;

__snapshots__/tsnapi/index.snapshot.js

@@ -0,0 +1,4 @@
+/**
+ * Generated by tsnapi — public API snapshot of `pkg-placeholder` */
+export var one /* const */
+export var two /* const */