Gridkit

Fixes
- Properly handle negative offsets in Rust grid classes

Misc
- Move the following methods to Rust:

- RectGrid.centroid
- RectGrid.cell_at_point
- RectGrid.cell_corners
- HexGrid.centroid
- HexGrid.cell_at_point
- HexGrid.cell_corners

This is done in preparation of rotation of un-bounded grids and provides a minor speedup.

Features
- Replace ``GridIndex._1d_view`` with :meth:`.GridIndex.index_1d`, which is an int64 instead of a custom data type.
- Replace ``index._nd_view`` with :meth:`.GridIndex.from_index_1d`

Fixes
- Remove redundant array allocation in :meth:`.TriGrid.cells_in_bounds`

Documentation
- Remove ``dask_geopandas`` dependency in example :ref:`aggregate_dask.py <example aggregate_dask>`. Use :meth:`.GridIndex.index_1d` instead.
- Use numpy array :meth:`.GridIndex.index_1d` in example :ref:`aggregate.py <example aggregate>` instead of a python list of :class:`.GridIndex` objects.

Fixes
- Remove allocation of unused array

Documentation
- Add building of Rust binary to the contributing guide

Misc
- Improve performance of BaseGrid.to_shapely

---------------------------------
Features
- Add `BoundedTriGrid`
- Improved performance of linear resampling for `BoundedHexGrid`
- "inverse_distance" interpolation method for `BoundedGrid.resample` and `BoundedGrid.interpolate`

Fixes
- Fixed incorrect cell returned for points in `TriGrid.cell_at_point` near the cell edge
- Allow for nd input in `TriGrid.cell_at_point`