setting llama-3-70b to default model

src/lib/components/Playground/Playground.svelte

@@ -52,7 +52,7 @@
 	let conversations: Conversation[] = [
 		{
 			id: String(Math.random()),
-			model: '01-ai/Yi-1.5-34B-Chat',
+			model: 'meta-llama/Meta-Llama-3-70B-Instruct',
 			config: { temperature: 0.5, maxTokens: 2048, streaming: true, jsonMode: false },
 			messages: startMessages
 		}