Updating CSI Contributions

* Clarify CLA must be mailed to approvers not community mailing list.
* Reword and reorganize the doc.

Author: saad-ali

CONTRIBUTING.md

@@ -1,10 +1,14 @@
 # How to Contribute
 
-CSI is under [Apache 2.0](LICENSE) and accepts contributions via GitHub pull requests.
+This document outlines some of the requirements and conventions for contributing to the Container Storage Interface, including development workflow, commit message formatting, contact points, and other resources to make it easier to get your contribution accepted.
+
+## Licence and CLA
 
-Contributions require signing an individual or Corporate CLA available [here](https://github.com/container-storage-interface/spec/blob/master/CCLA.pdf) which should be signed and mailed to the [mailing list]( https://groups.google.com/forum/#!topic/container-storage-interface-community/).
+CSI is under [Apache 2.0](LICENSE) and accepts contributions via GitHub pull requests.
 
-This document outlines some of the conventions on development workflow, commit message formatting, contact points and other resources to make it easier to get your contribution accepted.
+Before contributing to the Container Storage Interface, contributors MUST sign the CLA available [here](https://github.com/container-storage-interface/spec/blob/master/CCLA.pdf).
+The CLA MAY be signed on behalf of a company, possibly covering multiple contributors, or as an individual (put "Individual" for "Corporation name").
+The completed CLA MUST be mailed to the CSI Approvers [mailing list]([email protected]).
 
 ## Markdown style