Update README.md

README.md

@@ -25,8 +25,11 @@ Instantiate and use the client with the following:
 ```typescript
 import { CartesiaClient } from "@cartesia/cartesia-js";
 
-const client = new CartesiaClient({ apiKey: "YOUR_API_KEY_HEADER" });
-await client.tts.bytes({
+// Set up the client.
+const client = new CartesiaClient({ apiKey: "YOUR_API_KEY" });
+
+// Call the TTS API's bytes endpoint, which returns binary audio data as an ArrayBuffer.
+const response = await client.tts.bytes({
     modelId: "sonic-english",
     transcript: "Hello, world!",
     voice: {
@@ -40,6 +43,9 @@ await client.tts.bytes({
         encoding: "pcm_f32le",
     },
 });
+
+// Write the response to a file.
+fs.writeFileSync("sonic.wav", new Uint8Array(response));
 ```
 
 ### TTS over WebSocket