[Doc] Fix RayServeHandle doc (#10896)

python/ray/serve/handle.py

@@ -52,12 +52,12 @@ class RayServeHandle:
 
         Returns:
             ray.ObjectRef
-        Input:
+        Args:
             request_data(dict, Any): If it's a dictionary, the data will be
-              available in ``request.json()`` or ``request.form()``. Otherwise,
-              it will be available in ``request.data``.
+                available in ``request.json()`` or ``request.form()``.
+                Otherwise, it will be available in ``request.data``.
             ``**kwargs``: All keyword arguments will be available in
-              ``request.args``.
+                ``request.args``.
         """
         request_metadata = RequestMetadata(
             self.endpoint_name,