Merge branch 'v2.0' into master

docs/en_US/nas.rst

@@ -21,6 +21,7 @@ For details, please refer to the following tutorials:
     Write A Search Space <NAS/WriteSearchSpace>
     Classic NAS <NAS/ClassicNas>
     One-shot NAS <NAS/one_shot_nas>
+    Retiarii NAS (experimental) <NAS/retiarii/retiarii_index>
     Customize a NAS Algorithm <NAS/Advanced>
     NAS Visualization <NAS/Visualization>
     Search Space Zoo <NAS/SearchSpaceZoo>

docs/en_US/nnicli_ref.rst

 NNI Client
 ==========
 
-NNI client is a python API of ``nnictl``\ , which implements the most commonly used commands. Users can use this API to control their experiments, collect experiment results and conduct advanced analyses based on experiment results in python code directly instead of using command line. Here is an example:
+NNI client is a python API of ``nnictl``, which implements the most commonly used commands. Users can use this API to control their experiments, collect experiment results and conduct advanced analyses based on experiment results in python code directly instead of using command line. Here is an example:
 
 .. code-block:: bash
 
-   from nni.experiment import Experiment
+   from nni.experiment import LegacyExperiment
 
    # create an experiment instance
-   exp = Experiment() 
+   exp = LegacyExperiment()
 
    # start an experiment, then connect the instance to this experiment
    # you can also use `resume_experiment`, `view_experiment` or `connect_experiment`
@@ -25,17 +25,3 @@ NNI client is a python API of ``nnictl``\ , which implements the most commonly u
 
    # stop the experiment, then disconnect the instance from the experiment.
    exp.stop_experiment()
-
-References
-----------
-
-..  autoclass:: nni.experiment.Experiment
-    :members:
-..  autoclass:: nni.experiment.TrialJob
-    :members:
-..  autoclass:: nni.experiment.TrialHyperParameters
-    :members:
-..  autoclass:: nni.experiment.TrialMetricData
-    :members:
-..  autoclass:: nni.experiment.TrialResult
-    :members:

docs/en_US/reference.rst

@@ -11,3 +11,4 @@ References
     NNI Annotation <Tutorial/AnnotationSpec>
     SDK API References <sdk_reference>
     Supported Framework Library <SupportedFramework_Library>
+    Launch from python <Tutorial/HowToLaunchFromPython>

docs/en_US/training_services.rst

@@ -6,10 +6,9 @@ Introduction to NNI Training Services
     Local<./TrainingService/LocalMode>
     Remote<./TrainingService/RemoteMachineMode>
     OpenPAI<./TrainingService/PaiMode>
-    OpenPAI Yarn Mode<./TrainingService/PaiYarnMode>
     Kubeflow<./TrainingService/KubeflowMode>
     AdaptDL<./TrainingService/AdaptDLMode>
     FrameworkController<./TrainingService/FrameworkControllerMode>
     DLTS<./TrainingService/DLTSMode>
     AML<./TrainingService/AMLMode>
-    Heterogeneous<./TrainingService/HeterogeneousMode>
+    Hybrid<./TrainingService/HybridMode>