Update README.md

update branch names

Author: tedhudek

README.md

@@ -4,8 +4,8 @@ Welcome to the Windows driver docs repository, housing the source for the offici
 
 ## Contributing
 
-We actively merge contributions into this repository via [pull request](https://help.github.com/articles/using-pull-requests/) into the *master* branch. 
-If not are not a Microsoft employee, please note that before you submit a pull request you must [sign a Contribution License Agreement](https://cla.microsoft.com/) to ensure that the community is free to use your submissions.
+We actively merge contributions into this repository via [pull request](https://help.github.com/articles/using-pull-requests/) into the *staging* branch (for the public repo) or the *master* branch (for the private repo). 
+
 For more information on contributing, read our [contributions guide](CONTRIBUTING.md).
 
 ## Microsoft Code of Conduct