"Optional" Dependencies for CLI

[CaptainInler]

The Documentation lists some Dependencies as optional.
As far as I can see, these optional dependencies are all required for the CLI. Some are even marked as required for the CLI, others, like python-geohash, are not obviously required.
Is it intended that all dependencies are required for the CLI? If so, I will try to update the documentation accordingly.

[RaczeQ]

Hi, it is true that all optional dependencies are only required for CLI currently.
I forgot to copy this information for all listed packages in readme (missing in s2 and geohash).