Copyright and license per file:
* everything in `extern/dilithium2`, `extern/dilithium3` and `extern/dilithium5` was originally
  copied from the `pqclean` project (<https://github.com/PQClean/PQClean>), but modified
  afterwards. The original was licensed CC0 / Public domain, and so are any modifications.
* everything in `extern/common` is copied from the `pqclean` project
  (<https://github.com/PQClean/PQClean>), and unmodified. These files contain licensing information
  at the top of the file, and are all either in public domain / CC0 or MIT licensed.
* `scripts/generate_api_h.py`, `scripts/generate_sign_c.py` and `scripts/generate_sign_h.py` are
  based on the C code in `extern/dilithium2`, `extern/dilithium3` and `extern/dilithium5` and also
  licensed CC0 / Public domain.
* everything else is original work from the crate authors,
  Copyright (c) 2022 niluxv <niluxv.opensource.C-h2ty6xl@yandex.com>
  and licensed under the MIT license <LICENSE.MIT> or the Apache License, Version 2.0
  <LICENSE.APACHE>, at your option.

TLDR: everything can be used under the conditions of the MIT license.

Note: This crate is by no means endorsed by the `pqclean` project!

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT
NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM,
DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT
OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.