[Serve] Fix the serve.batch api doc (ray-project#33588)

Fix the example formatting in the serve batch API doc

Signed-off-by: elliottower <elliot@elliottower.com>

python/ray/serve/batching.py

@@ -228,14 +228,13 @@ def batch(_func=None, max_batch_size=10, batch_wait_timeout_s=0.0):
     or `batch_wait_timeout_s` has elapsed, whichever occurs first.
 
     Example:
-    >>> from ray import serve
-    >>> @serve.batch(max_batch_size=50, batch_wait_timeout_s=0.5) # doctest: +SKIP
-    ... async def handle_batch(batch: List[str]): # doctest: +SKIP
-    ...     return [s.lower() for s in batch] # doctest: +SKIP
-
-    >>> async def handle_single(s: str): # doctest: +SKIP
-    ...     # Returns s.lower().
-    ...     return await handle_batch(s) # doctest: +SKIP
+        >>> from ray import serve
+        >>> @serve.batch(max_batch_size=50, batch_wait_timeout_s=0.5) # doctest: +SKIP
+        ... async def handle_batch(batch: List[str]): # doctest: +SKIP
+        ...     return [s.lower() for s in batch] # doctest: +SKIP
+        >>> async def handle_single(s: str): # doctest: +SKIP
+        ...     # Returns s.lower().
+        ...     return await handle_batch(s) # doctest: +SKIP
 
     Arguments:
         max_batch_size: the maximum batch size that will be executed in