re-add addCustomEvent function via function property

src/index.ts

@@ -1,4 +1,4 @@
-import record, { addCustomEvent } from './record';
+import record from './record';
 import { Replayer } from './replay';
 import { mirror } from './utils';
 
@@ -8,4 +8,7 @@ export {
   MouseInteractions,
   ReplayerEvents,
 } from './types';
+
+const { addCustomEvent } = record;
+
 export { record, addCustomEvent, Replayer, mirror };