[DOCS] Upsert documentation clarification

specification/_global/update/UpdateRequest.ts

@@ -180,8 +180,9 @@ export interface Request<TDocument, TPartialDocument> extends RequestBase {
      */
     _source?: SourceConfig
     /**
+     * Upserts are powerful operations that enable you to perform both update and insert actions in a single request.
      * If the document does not already exist, the contents of 'upsert' are inserted as a new document.
-     * If the document exists, the 'script' is run.
+     * If the document exists, the script is run.
      * @prop_serializer SourceFormatter`1
      */
     upsert?: TDocument

specification/_global/update/examples/request/UpdateRequestExample9.yaml

@@ -1,10 +1,8 @@
 summary: Upsert
 # method_request: POST test/_update/1
 description: >
-  Run `POST test/_update/1` to perfom an upsert.
-  If the document does not already exist, the contents of the upsert element are inserted as a new document. If the document exists, the script is run.
+  Run `POST test/_update/1` to perfom update and insert actions in a single request.
+  In this example, if the product with ID 1 exists, its price will be updated to 100.
+  If the product does not exist, a new document with ID 1 and a price of 50 will be inserted.
 # type: request
-value:
-  "{\n  \"script\": {\n    \"source\": \"ctx._source.counter += params.count\"\
-  ,\n    \"lang\": \"painless\",\n    \"params\": {\n      \"count\": 4\n    }\n \
-  \ },\n  \"upsert\": {\n    \"counter\": 1\n  }\n}"
+value: { 'doc': { 'product_price': 100 }, 'upsert': { 'product_price': 50 } }