message: Update the generate2 doc injection.
diff: python generate2.py --output_dir=/tmp/out
  ```
  -Requires a local installation of:
  - https://github.com/tensorflow/docs/tree/master/tools
  - tf-nightly-2.0-preview
  +Requires a local installation of `tensorflow_docs`:
  +
  + ```
  + pip install git+https://github.com/tensorflow/docs
  + ```
  """
  from __future__ import absolute_import
  @@ -137,19 +139,10 @@ else:
  }
  DO_NOT_DESCEND_MAP = {}
  tf.__doc__ = """
  - ## TensorFlow 2.0 RC
  -
  - Caution: This is a developer preview. You will likely find some bugs,
  - performance issues, and more, and we encourage you to tell us about them.
  - We value your feedback!
  -
  - These docs were generated from the beta build of TensorFlow 2.0.
  -
  - You can install the exact version that was used to generate these docs
  - with:
  + ## TensorFlow
  ```
  - pip install tensorflow==2.0.0-rc0
  + pip install tensorflow
  ```
  """
  