Geowrangler

New Features

- `FastSquareGridGenerator` as a faster equivalent to `SquareGridGenerator` (PR [253](https://github.com/thinkingmachines/geowrangler/pull/253)) from [joshuacortez](https://github.com/joshuacortez)
- Just like `FastBingTileGenerator`, this is also added in `00_grids.ipynb`.

Improvements
- The `generate_grid` method in `SquareGridGenerator` and `FastSquareGridGenerator` shows a warning when the boundary of doesn't fully enclose the AOI. (issue [147](https://github.com/thinkingmachines/geowrangler/issues/147))

New Features

- `FastBingTileGenerator` for significantly speeding up grid generation ([245](https://github.com/thinkingmachines/geowrangler/pull/245)), thanks to [joshuacortez](https://github.com/joshuacortez)
- This PR adds a new gridding class `FastBingTileGenerator` that significantly speeds up grid generation. This is added in `00_grids.ipynb`.

- `Exactextract zonal stats` method for a faster raster zonal stats implementation based on `exactextract` python package ([236](https://github.com/thinkingmachines/geowrangler/pull/236)), thanks to [tm-jc-nacpil](https://github.com/tm-jc-nacpil)

- This PR adds a new method `create_raster_zonal_stats_exactextract` that uses the `exactextract` python package for a faster raster zonal stats implementation. This is added in `02_raster_zonal_stats.ipynb`.

- Documentation updates: updated the Development, Contributing and Release sections of the documentation to reflect the new development and release processes.

Features

- Implemented `GridGenerator`
- Implemented `GeometryValidation`
- Implemented `VectorZonalStats`
- Implemented `RasterZonalStats`
- Implemented `AreaZonalStats`
- Implemented `DistanceZonalStats`
- Implemented dataset download for ookla and geofabrik
- Implemented DHS utility functions