[docs] fix: fix markdown syntax (#18927)

docs/design/arch_overview.md

@@ -48,8 +48,7 @@ for output in outputs:
     print(f"Prompt: {prompt!r}, Generated text: {generated_text!r}")
 ```
 
-More API details can be found in the [Offline Inference]
-(#offline-inference-api) section of the API docs.
+More API details can be found in the [Offline Inference](#offline-inference-api) section of the API docs.
 
 The code for the `LLM` class can be found in <gh-file:vllm/entrypoints/llm.py>.