Module-utilities

Changed

- Revert to TypeVar `S` being invariant. This leads to some issues with
`cached.prop` decorator. However, the use of covariant `TypeVar` was a hack.
Instead, it is better in these cases to decorate with `property` on top of
`cached.meth`. mypy/pyright deal with `property` in a special way.
- To better work with the above, single parameter methods are caached using only
the method name, and no parameters.

Changed

- Moved submodule `_typing` to `typing` (i.e., publicly accessible).
- Made TypeVar `S` covariant. This fixes issues with subclassing overrides.

Changed

- Simplified cached.prop by using (new) CachedProperty class.

Added

- Now include module `docinhert` to interface with
[docstring-inheritance](https://github.com/AntoineD/docstring-inheritance)
- Fully support mypy and pyright type checking.

Added

- Add `_prepend` option to docfiller. Default behavior is now to append current
docstring to templates.

Added

- Package now available on conda-forge

Changed

- Properly vendor numpydocs and include pointer to license