Merge pull request #1435 from mattray/notice

Initial NOTICE based off of Apache recommendations

NOTICE

@@ -0,0 +1,9 @@
+OpenCost
+Copyright 2022 Cloud Native Computing Foundation
+
+This product includes software developed at
+The Cloud Native Computing Foundation (http://www.cncf.io).
+
+The Initial Developer of some parts of the specification and project is
+Kubecost (http://www.kubecost.com).
+Copyright 2019 - 2022 Stackwatch Incorporated. All Rights Reserved.