Add mailing list to README and documentation. (#950)

* Add mailing list to documentation.

* Add contact page to documentation.

README.rst

@@ -24,10 +24,12 @@ Installation
 More Information
 ----------------
 
+- `Mailing List`_
 - `Documentation`_
 - `Blog`_
 - `HotOS paper`_
 
+.. _`Mailing List`: https://groups.google.com/forum/#!forum/ray-dev
 .. _`Documentation`: http://ray.readthedocs.io/en/latest/index.html
 .. _`Blog`: https://ray-project.github.io/ray/
 .. _`HotOS paper`: https://arxiv.org/abs/1703.03924

doc/source/contact.rst

@@ -0,0 +1,11 @@
+Contact
+=======
+
+The following are good places to discuss Ray.
+
+1. `Our Mailing List`_: For discussions about development, questions about
+   usage, or any general questions.
+2. `GitHub Issues`_: For bug reports and feature requests.
+
+.. _`Our Mailing List`: https://groups.google.com/forum/#!forum/ray-dev
+.. _`GitHub Issues`: https://github.com/ray-project/ray/issues

doc/source/index.rst

@@ -55,3 +55,4 @@ Ray
    :caption: Help
 
    troubleshooting.rst
+   contact.rst