new features
- implement spelled array types
- vectorized operations (using numpy)
- supports array interface (indexing, iteration, etc.)
- add one-hot encoding/decoding for all spelled types
breaking changes
- update definition of "direction" on spelled types
- now altered unisons have a direction (except the perfect unison) for spelled types
- `d1:0` is now normalized to `-a1:0` (because `d1:0` is considered downward)
- compliant with the other libraries
- remove `generic` and `diatonic_steps` from spelled pitch types
- both don't make sense (conceptually) for pitches
- potentially leak the underlying interval representation
- only degree is meaningful for pitches
improvements
- better docstring formatting (parameters and return values)
bug fixes
- implement ordering for spelled types in a consistent way
- add docs
- fixes bug where `Cb-1 > C-1` was true