fix(retail): add region tag for node.js - Update add fullfillment places (#4120)

* Update search-simple-query.js

Added region tag to simply search query for code snippet update in the documentation.

* Update search-with-pagination.js

* Update add-fulfillment-places.js

---------

Co-authored-by: Katie McLaughlin <[email protected]>

Author: rebeccaellis

retail/interactive-tutorials/product/add-fulfillment-places.js

@@ -13,7 +13,7 @@
 // limitations under the License.
 
 'use strict';
-
+// [START retail_add_fulfillment_places]
 async function main(generatedProductId) {
   // Imports the Google Cloud client library.
   const {ProductServiceClient} = require('@google-cloud/retail').v2;
@@ -89,3 +89,4 @@ process.on('unhandledRejection', err => {
 });
 
 main(...process.argv.slice(2));
+// [END retail_add_fulfillment_places]