Add string array to EndpointParameters (#1358)

Author: trivikr

.changeset/lazy-grapes-drive.md

@@ -0,0 +1,5 @@
+---
+"@smithy/types": minor
+---
+
+Add string array to EndpointParameters

packages/types/src/endpoint.ts

@@ -85,4 +85,4 @@ export interface EndpointV2 {
 /**
  * @public
  */
-export type EndpointParameters = { [name: string]: undefined | string | boolean };
+export type EndpointParameters = { [name: string]: undefined | boolean | string | string[] };