Move xgboost section in docs

Author: edwardjkim

doc/v2.rst

@@ -203,6 +203,12 @@ To view logs after attaching a training job to an estimator, use :func:`sagemake
 until the completion of the Hyperparameter Tuning Job or Batch Transform Job, respectively.
 To make the function non-blocking, use ``wait=False``.
 
+XGBoost Predictor
+-----------------
+
+The default serializer of ``sagemaker.xgboost.model.XGBoostPredictor`` has been changed from ``NumpySerializer`` to ``LibSVMSerializer``.
+
+
 Parameter and Class Name Changes
 ================================
 
@@ -327,11 +333,6 @@ TensorFlow Serving Predictor
 ``sagemaker.tensorflow.serving.Predictor`` has been renamed to :class:`sagemaker.tensorflow.model.TensorFlowPredictor`.
 (For the previous implementation of that class, see `Deprecate Legacy TensorFlow <#deprecate-legacy-tensorflow>`_).
 
-XGBoost Predictor
-~~~~~~~~~~~~~~~~~
-
-The default seriazlier of ``sagemaker.xgboost.model.XGBoostPredictor`` has been changed from ``NumpySerializer`` to ``LibSVMSerializer``.
-
 
 Inputs
 ------