Update quick start examples (#120)

python/sglang/srt/models/qwen2.py

@@ -8,7 +8,6 @@ from sglang.srt.layers.logits_processor import LogitsProcessor
 from sglang.srt.layers.radix_attention import RadixAttention
 from sglang.srt.managers.router.model_runner import InputMetadata
 from torch import nn
-from transformers import Qwen2Config
 from vllm.model_executor.layers.activation import SiluAndMul
 from vllm.model_executor.layers.layernorm import RMSNorm
 from vllm.model_executor.layers.linear import (
@@ -30,6 +29,8 @@ from vllm.model_executor.weight_utils import (
     hf_model_weights_iterator,
 )
 
+Qwen2Config = None
+
 
 class Qwen2MLP(nn.Module):
     def __init__(