Document Tuning Engines OpenAI-compatible configuration

docs/en/learn/llm-connections.mdx

@@ -156,6 +156,17 @@ You can connect to OpenAI-compatible LLMs using either environment variables or
             agent = Agent(llm=llm, ...)
             ```
 
+            ```python Tuning Engines
+            # Example using Tuning Engines OpenAI-compatible endpoint.
+            # Use a model alias from your Tuning Engines catalog.
+            llm = LLM(
+                model="your-model-alias",
+                api_key="your-tuning-engines-key",
+                base_url="https://api.tuningengines.com/v1"
+            )
+            agent = Agent(llm=llm, ...)
+            ```
+
             ```python Google
             # Example using Gemini's OpenAI-compatible API
             llm = LLM(