add NOTICE file with government statement

NOTICE

@@ -0,0 +1,21 @@
+Copyright 2024 Jason A. Regina and Austin Raney
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+
+Software code created by U.S. Government employees is not subject to copyright in the
+United States (17 U.S.C. §105). The United States/Department of Commerce reserves
+all rights to seek and obtain copyright protection in countries other than the United
+States for Software authored in its entirety by the Department of Commerce. To this end,
+the Department of Commerce hereby grants to Recipient a royalty-free, nonexclusive
+license to use, copy, and create derivative works of the Software outside of the United
+States.