DOC: Enhance the documentation

[remi-braun]

Enhance documentation, following these axis:

• Add notebooks, one per usecases or per module (?)
• Link other documentations in intersphinx_mapping
  • cloudpathlib for CloudPath
  • xarray for DataArray / Dataset
  • geopandas for GeoDataFrames
  • numpy ?
• Add examples for functions that miss some
• Add :py:func: to create links to relevant functions
• Add :any: to create cross-references (see https://www.sphinx-doc.org/en/master/usage/referencing.html#role-any)
• Add external reference to the libraries mentioned above (i.e. :class:`rasterio:rasterio.enums.Resampling` )
• Double ticks to add formatted text
• Change .. WARNING:: to Warnings
• ...

See fb7f636 for an overview of what should be done 🔥