Update FAQ example to include async

Author: YoanSallami

docs/FAQ.md

@@ -162,32 +162,39 @@ Example:
 
 ```python
 import synalinks
-
-class ThinkingWithAnswer(synalinks.DataModel):
-    thinking: str
-    answer: str
-
-language_model = synalinks.LanguageModel("ollama_chat/deepseek-r1")
-
-program = synalinks.Sequential(
-    [
-        synalinks.Generator(
-            data_model=ThinkingWithAnswer,
-            language_model=language_model,
-        ),
-        synalinks.Generator(
-            data_model=ThinkingWithAnswer,
-            language_model=language_model,
-        ),
-    ]
-)
-
-program.modules[0].trainable = False # Freeze the first generator
-
-assert program.modules[0].trainable_variables == []
-
-program.compile(...)
-program.fit(...) # Train only the second generator
+import asyncio
+
+async def main():
+    class ThinkingWithAnswer(synalinks.DataModel):
+        thinking: str
+        answer: str
+
+    language_model = synalinks.LanguageModel(
+        "ollama_chat/deepseek-r1",
+    )
+
+    program = synalinks.Sequential(
+        [
+            synalinks.Generator(
+                data_model=ThinkingWithAnswer,
+                language_model=language_model,
+            ),
+            synalinks.Generator(
+                data_model=ThinkingWithAnswer,
+                language_model=language_model,
+            ),
+        ]
+    )
+
+    program.modules[0].trainable = False # Freeze the first generator
+
+    assert program.modules[0].trainable_variables == []
+
+    program.compile(...)
+    history = await program.fit(...) # Train only the second generator
+
+if __main__ == "__name__":
+    asyncio.run(main())
 ```
 
 In essence, "inference mode vs training mode" and "module variable trainability" are two very different concepts.