Change example model to SmolLM2-135M-Instruct in README

Signed-off-by: Eric Curtin <eric.curtin@docker.com>

Author: ericcurtin

README.md

@@ -61,7 +61,7 @@ export VLLM_METAL_ENABLE_PROFILING=1
 
 # Run vLLM
 python -m vllm.entrypoints.openai.api_server \
-    --model meta-llama/Llama-2-7b-hf \
+    --model HuggingFaceTB/SmolLM2-135M-Instruct \
     --dtype float16
 ```