Update lib/index.d.ts

Co-authored-by: Enric Bisbe Gil <[email protected]>

Author: zirkelc

lib/index.d.ts

@@ -145,6 +145,9 @@ interface Map extends StateBase {
   Type: 'Map';
   ItemsPath: string;
   Iterator: Definition;
+  ItemSelector: {
+    [key: string]: string;
+  }
   MaxConcurrency?: number;
   Parameters?: {
     [key: string]: string;