samples: Update quickstart.js (#189)

include the required region if using EU based processor (defaults to US)

Co-authored-by: Justin Beckwith <[email protected]>

Author: mtannerfors

document-ai/snippets/quickstart.js

@@ -29,6 +29,8 @@ async function main(projectId, location, processorId, filePath) {
     require('@google-cloud/documentai').v1;
 
   // Instantiates a client
+  // apiEndpoint regions available: eu-documentai.googleapis.com, us-documentai.googleapis.com (Required if using eu based processor)
+  // const client = new DocumentProcessorServiceClient({apiEndpoint: 'eu-documentai.googleapis.com'});
   const client = new DocumentProcessorServiceClient();
 
   async function quickstart() {