Create CONTRIBUTING.md

Author: pijaro

CONTRIBUTING.md

@@ -0,0 +1,11 @@
+Any contribution that you make to this repository will
+be under the Apache 2 License, as dictated by that
+[license](http://www.apache.org/licenses/LICENSE-2.0.html):
+
+> 5. Submission of Contributions. Unless You explicitly state otherwise,
+>    any Contribution intentionally submitted for inclusion in the Work
+>    by You to the Licensor shall be under the terms and conditions of
+>    this License, without any additional terms or conditions.
+>    Notwithstanding the above, nothing herein shall supersede or modify
+>    the terms of any separate license agreement you may have executed
+>    with Licensor regarding such Contributions.