Update README.md (#15)

* Update README.md

* videoframes example

* fix indents

* fix indents x2

README.md

@@ -1,5 +1,6 @@
 # LiveKit: Native SDK
-
+![crates.io](https://img.shields.io/crates/v/livekit.svg)
+[![Tests & Build](https://github.com/livekit/client-sdk-native/actions/workflows/rust.yml/badge.svg?branch=main)](https://github.com/livekit/client-sdk-native/actions/workflows/rust.yml)
 > **Warning**
 > This SDK is a developer preview and is not ready for production use. There will be bugs and the APIs may change during this period.
 > All feedbacks/contributions are appreciated. You can create issues or discuss with us on the #rust-developer-preview channel in our [Slack](https://livekit.io/join-slack)
@@ -64,6 +65,26 @@ async fn main() -> Result<()> {
 }
 ```
 
+### Receive video frames of a subscribed track
+
+```rust
+match event {
+   RoomEvent::TrackSubscribed { track, publication, participant } => {
+      if let RemoteTrackHandle::Video(video_track) => {
+          let rtc_track = video_track.rtc_track();
+          rtc_track.on_frame(Box::new(move |frame, buffer| {
+              // Just received a video frame!
+              // The buffer is YuvEncoded, you can decode it to ABGR by using our yuv_helper
+              // See the simple_room example for the conversion 
+          });
+      } else {
+          // Audio Track..
+      }
+   }
+   _ => {}
+}
+```
+
 ## Examples
 
 We made [simple room](https://github.com/livekit/client-sdk-native/tree/main/examples/simple_room) demo using all features of the SDK. We render videos using wgpu and egui.