Enable thinking by default in non-Hopper FP8-KV serve command

Adds --default-chat-template-kwargs '{"enable_thinking": true}' to the workaround command so it matches the main card's recommended invocation.

README.md

@@ -106,6 +106,7 @@ The full vLLM recipe is on the main [Laguna XS.2 model card](https://huggingface
 >     --reasoning-parser poolside_v1 \
 >     --enable-auto-tool-choice \
 >     --served-model-name laguna \
+>     --default-chat-template-kwargs '{"enable_thinking": true}' \
 >     --kv-cache-dtype-skip-layers $(seq 0 39) \
 >     --moe_backend marlin
 > ```