[ethers-v5] Add changeset for directory moduleSuffix change

Author: chmanie

.changeset/lazy-eggs-brush.md

@@ -0,0 +1,6 @@
+---
+'typechain': patch
+---
+
+Add the node16 moduleSuffix also to directories (including the `index` filename) as in ESM directory root files have to
+be explicitly stated (including their file extension).