Update docs/Whats-New.md

Co-authored-by: Copilot <175728472+Copilot@users.noreply.github.com>

Author: TaranDahl

docs/Whats-New.md

@@ -554,6 +554,7 @@ New:
 - Customize which parasite can remove by warhead (by NetsuNegi)
 - Add toggle of whether shield use ArmorMultiplier or not (by NetsuNegi)
 - [Export interface for external call](../README.md#interoperability) (by TaranDahl)
+- [Export interface for external call](index.md#interoperability) (by TaranDahl)
 
 Vanilla fixes:
 - Fixed sidebar not updating queued unit numbers when adding or removing units when the production is on hold (by CrimRecya)