Point agents readme to main (#363)

Author: MaxHeimbrock

Samples~/Agents/README.md

@@ -4,7 +4,7 @@ Connect to a voice AI agent.
 
 ## Tutorial
 
-<img  style="width:1000px;"  alt="Screenshot of the LiveKit Unity SDK Youtube tutorial"  src="https://media.githubusercontent.com/media/livekit/client-sdk-unity/refs/heads/max/final-docs-update-for-2.0.0/.github/youtube_tutorial_screenshot.png">
+<img  style="width:1000px;"  alt="Screenshot of the LiveKit Unity SDK Youtube tutorial"  src="https://media.githubusercontent.com/media/livekit/client-sdk-unity/refs/heads/main/.github/youtube_tutorial_screenshot.png">
 
 [Youtube Agents NPC Tutorial](https://www.youtube.com/watch?v=cLreGfOKzN8)