- Promise cancellation improvements ([commit](https://github.com/miguelgrinberg/promisio/commit/29c9a4973fda789f6bd937a47e44bacdffb2265e))
- Added a short example in readme file ([commit](https://github.com/miguelgrinberg/promisio/commit/3c38c0aefd59186c33b5688a65235b7b51709cca))
- Sphinx documentation ([commit](https://github.com/miguelgrinberg/promisio/commit/92af9b0ee9e88b9096d609a9c7466a88cd6ee301))