updated example in README to match updated start method

experimental/packages/opentelemetry-sdk-node/README.md

@@ -58,11 +58,7 @@ const sdk = new opentelemetry.NodeSDK({
   // See the Configuration section below for additional  configuration options
 });
 
-// You can optionally detect resources asynchronously from the environment.
-// Detected resources are merged with the resources provided in the SDK configuration.
-sdk.start().then(() => {
-  // Resources have been detected and SDK is started
-});
+sdk.start();
 
 // You can also use the shutdown method to gracefully shut down the SDK before process shutdown
 // or on some operating system signal.