Add support for multiple knn queries (#2078) (#2079)

Co-authored-by: Sylvain Wallez <[email protected]>

Author: github-actions[bot]

output/schema/schema.json

@@ -101,7 +101,7 @@ export class MultisearchBody {
    * Defines the approximate kNN search to run.
    * @since 8.4.0
    */
-  knn?: KnnQuery
+  knn?: KnnQuery | KnnQuery[]
   /**
    * Starting document offset. By default, you cannot page through more than 10,000
    * hits using the from and size parameters. To page through more hits, use the

output/typescript/types.ts

@@ -161,7 +161,7 @@ export interface Request extends RequestBase {
      * Defines the approximate kNN search to run.
      * @since 8.4.0
      */
-    knn?: KnnQuery
+    knn?: KnnQuery | KnnQuery[]
     /**
      * Minimum _score for matching documents. Documents with a lower _score are
      * not included in the search results.