Move the 'CONTRIBUTING.md' file into the main repository. (googledata…

…lab#1144)

This was previously in the wiki repository (and linked to from
the README), but putting it in the main repository makes it easier
for potential contributors to find.

CONTRIBUTING.md

@@ -0,0 +1,17 @@
+Want to contribute? Great! First, read this page (including the small print at the end).
+
+### Before you contribute
+Before we can use your code, you must sign the
+[Google Individual Contributor License Agreement](https://developers.google.com/open-source/cla/individual?csw=1)
+(CLA), which you can do online. The CLA is necessary mainly because you own the copyright to your changes, even after your contribution becomes part of our codebase, so we need your permission to use and distribute your code. We also need to be sure of various other things. For instance that you'll tell us if you know that your code infringes on other people's patents. You don't have to sign the CLA until after you've submitted your code for review and a member has approved it, but you must do it before we can put your code into our codebase.
+
+Before you start working on a larger contribution, we recommend to get in touch with us first through the issue tracker with your idea so that we can help out and possibly guide you. Coordinating up front makes it much easier to avoid frustration later on.
+
+### Code reviews
+All submissions, including submissions by project members, require review. We use GitHub pull requests for this purpose.
+
+### Organization
+During our review and triage of incoming pull requests, we'll advise whether to include your contribution into the DataLab product, or maintain it as an installable, but separate component or library.
+
+### The small print
+Contributions made by corporations are covered by a different agreement than the one above, the Software Grant and Corporate Contributor License Agreement.

README.md

@@ -49,7 +49,7 @@ and the developer workflow.
 ### Contributing
 
 Contributions are welcome! Please see our [roadmap](https://github.com/googledatalab/datalab/wiki/Roadmap)
-page. Please check the page on [contributing](https://github.com/googledatalab/datalab/wiki/Contributing)
+page. Please check the page on [contributing](https://github.com/googledatalab/datalab/blob/master/CONTRIBUTING.md)
 for more details.
 
 You can always contribute even without code submissions by submitting issues and suggestions to