0.1.0

- Introduce `Signal.Gate.t` and `Signal.Trigger.t` wrappers of `bool Signal.t`
- Rename `clock` constructor to `clock_of_frequency_hz`
- Use `floatarray` instead of `float array`
- Add `saturation` operator
- Add `map2` and `map3` combinators
- Add missing `downsample` argument to visualized signal players
- Stop exporting labelled stdlib modules
- Add tests in new package
- Rename filter arguments to be more consistent and intuitive
- Rename `Square` waveform to `Pulse`
- Live midi support in core library
- Add package for parsing and representing midi data
- Rename ASR envelope generator to "AR"
- Rename `Output_stream.create_with_downsample` to `Output_stream.create`