Add Zero Clause BSD license

close #642

_licenses/0bsd.txt

@@ -0,0 +1,41 @@
+---
+title: Zero Clause BSD
+spdx-id: 0BSD
+
+description: The Zero Clause BSD license goes further than the BSD 2-Clause license to allow you unlimited freedom with the software _without_ the requirements to include the copyright notice, license text, or disclaimer in either source or binary forms.
+
+how: Create a text file (typically named LICENSE or LICENSE.txt) in the root of your source code and copy the text of the license into the file.  Replace [year] with the current year and [fullname] [email] with the name and contact email address of each copyright holder. You may take the additional step of removing the copyright notice, license text, or disclaimer.
+
+using:
+  - Toybox: https://github.com/landley/toybox/blob/master/LICENSE
+  - smoltcp: https://github.com/m-labs/smoltcp/blob/master/LICENSE-0BSD.txt
+  - PickMeUp: https://github.com/nazar-pc/PickMeUp/blob/master/copying.md
+
+permissions:
+  - commercial-use
+  - modifications
+  - distribution
+  - private-use
+
+conditions: []
+
+limitations:
+  - liability
+  - warranty
+
+---
+
+Zero Clause BSD
+
+Copyright (C) [year] by [fullname] <[email]>
+
+Permission to use, copy, modify, and/or distribute this software for any
+purpose with or without fee is hereby granted.
+
+THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH
+REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY
+AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY SPECIAL, DIRECT,
+INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM
+LOSS OF USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR
+OTHER TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR
+PERFORMANCE OF THIS SOFTWARE.