Update browser.md (#5667)

Author: EkkoLee98

content/en/docs/languages/js/getting-started/browser.md

@@ -166,8 +166,9 @@ import { DocumentLoadInstrumentation } from '@opentelemetry/instrumentation-docu
 import { ZoneContextManager } from '@opentelemetry/context-zone';
 import { registerInstrumentations } from '@opentelemetry/instrumentation';
 
-const provider = new WebTracerProvider();
-provider.addSpanProcessor(new SimpleSpanProcessor(new ConsoleSpanExporter()));
+const provider = new WebTracerProvider({
+  spanProcessors: [new SimpleSpanProcessor(new ConsoleSpanExporter())],
+});
 
 provider.register({
   // Changing default contextManager to use ZoneContextManager - supports asynchronous operations - optional