Add license file

LICENSE.md

+# NIST Disclaimer of Copyright and Warranty
+
+This software was developed by employees of the National Institute of
+Standards and Technology (NIST), an agency of the Federal Government
+and is being made available as a public service. Pursuant to title 17
+United States Code Section 105, works of NIST employees are not
+subject to copyright protection in the United States. This software
+may be subject to foreign copyright. Permission in the United States
+and in foreign countries, to the extent that NIST may hold copyright,
+to use, copy, modify, create derivative works, and distribute this
+software and its documentation without fee is hereby granted on a
+non-exclusive basis, provided that this notice and disclaimer of
+warranty appears in all copies.
+
+THE SOFTWARE IS PROVIDED 'AS IS' WITHOUT ANY WARRANTY OF ANY KIND,
+EITHER EXPRESSED, IMPLIED, OR STATUTORY, INCLUDING, BUT NOT LIMITED
+TO, ANY WARRANTY THAT THE SOFTWARE WILL CONFORM TO SPECIFICATIONS,
+ANY IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR
+PURPOSE, AND FREEDOM FROM INFRINGEMENT, AND ANY WARRANTY THAT THE
+DOCUMENTATION WILL CONFORM TO THE SOFTWARE, OR ANY WARRANTY THAT THE
+SOFTWARE WILL BE ERROR FREE. IN NO EVENT SHALL NIST BE LIABLE FOR ANY
+DAMAGES, INCLUDING, BUT NOT LIMITED TO, DIRECT, INDIRECT, SPECIAL OR
+CONSEQUENTIAL DAMAGES, ARISING OUT OF, RESULTING FROM, OR IN ANY WAY
+CONNECTED WITH THIS SOFTWARE, WHETHER OR NOT BASED UPON WARRANTY,
+CONTRACT, TORT, OR OTHERWISE, WHETHER OR NOT INJURY WAS SUSTAINED BY
+PERSONS OR PROPERTY OR OTHERWISE, AND WHETHER OR NOT LOSS WAS
+SUSTAINED FROM, OR AROSE OUT OF THE RESULTS OF, OR USE OF, THE
+SOFTWARE OR SERVICES PROVIDED HEREUNDER.
\ No newline at end of file