message: Mention license in README
diff: @@ -11,3 +11,9 @@ The work-in-progress language documentation can be found under the [docs directo
  a user-level guide to the data description language
  - [Language specification](./docs/specification):
  a low level technical specification of the data description language
  +
  +## License
  +
  +The language is licensed under the terms of the Apache License (Version 2.0).
  +
  +See [LICENSE](./LICENSE) or http://www.apache.org/licenses/LICENSE-2.0 for details.
  