Updated the usage notebook to reflect latest functions

[wwwslinger]

Incorporate/replaced functions to leverage latlng_to_cell, cells_to_polygons, grid_ring, cells_to_polygons, and Polygon.outer in the simple usage.ipynb notebook.

[CLAassistant]

All committers have signed the CLA.

[Mikecom32]

Thanks for putting together a PR! I'm getting an error running your updated notebook, since the updates requires at least the 4.0.0 release of h3-py. Bumping the h3 version in requirements.txt to h3>=4.0.0b2 fixed the issue if you'd like to update the PR.