Merge pull request #29 from PSLmodels/master

update from forked repo

docs/_toc.yml

@@ -27,11 +27,9 @@ parts:
 - caption: About
   chapters:
   - file: about/history
-  - file: about/roadmap
   - file: about/releases
-  - file: about/changes
-  - file: about/upgrading
-  - file: about/license
+  - file: about/roadmap
+  - file: about/LICENSE
 - caption: Contributing
   chapters:
   - file: contributing/contributor_guide

docs/about/LICENSE.md

@@ -0,0 +1,22 @@
+License
+=======
+
+The Tax-Calculator project is in the public domain within the United States.
+
+Additionally, we waive copyright and related rights in the work worldwide through the CC0 1.0 Universal public domain dedication.
+
+## CC0 1.0 Universal Summary
+
+The text below is a human-readable summary of the [Legal Code](https://creativecommons.org/publicdomain/zero/1.0/legalcode):
+
+_No Copyright_
+
+The person who associated a work with this deed has dedicated the work to the public domain by waiving all of his or her rights to the work worldwide under copyright law, including all related and neighboring rights, to the extent allowed by law.
+
+You can copy, modify, distribute and perform the work, even for commercial purposes, all without asking permission.
+
+_Other Information_
+
+In no way are the patent or trademark rights of any person affected by CC0, nor are the rights that other persons may have in the work or in how the work is used, such as publicity or privacy rights.
+
+Unless expressly stated otherwise, the person who associated a work with this deed makes no warranties about the work, and disclaims liability for all uses of the work, to the fullest extent permitted by applicable law. When using or citing the work, you should not imply endorsement by the author or the affirmer.