Make distinct code and console admonitions so readers are less likely to miss them (#20585)

Signed-off-by: Harry Mellor <19981378+hmellor@users.noreply.github.com>

docs/features/quantization/gptqmodel.md

@@ -31,7 +31,7 @@ After installing GPTQModel, you are ready to quantize a model. Please refer to t
 
 Here is an example of how to quantize `meta-llama/Llama-3.2-1B-Instruct`:
 
-??? Code
+??? code
 
     ```python
     from datasets import load_dataset
@@ -69,7 +69,7 @@ python examples/offline_inference/llm_engine_example.py \
 
 GPTQModel quantized models are also supported directly through the LLM entrypoint:
 
-??? Code
+??? code
 
     ```python
     from vllm import LLM, SamplingParams