Test-merge from dev branch.

Copybara import of the project:

  - 64d8529 Merge pull request #529 from tensorflow/MarkDaoust-patch-1 by Mark Daoust <[email protected]>
  - fd22ce9 Merge pull request #530 from tensorflow/MarkDaoust-patch-1 by Mark Daoust <[email protected]>
  - a3deb78 TF 2 readme by Billy Lamberta <[email protected]>

PiperOrigin-RevId: 245128969

Author: MarkDaoust

site/en/r2/README.md

@@ -1,3 +1,8 @@
-# TensorFlow 2.0 updates
+# TensorFlow 2.0 Alpha
 
-Read the announcement: [TensorFlow 2.0 is coming](https://groups.google.com/a/tensorflow.org/d/msg/announce/qXfsxr2sF-0/jHQ77dr3DAAJ)
+TensorFlow 2.0 focuses on simplicity and ease of use, with updates like
+eager execution, intuitive higher-level APIs, and flexible model building
+on any platform.
+
+Read the Alpha guide and tutorials to get started:
+https://www.tensorflow.org/alpha