Add: Introduction for users new to Python geospatial

[m-cappi]

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User Story: 3702 - Introduction for users new to Python geospatial

Created a documentation to introduce things for users who are new to (Python) geospatial.

It covers a landscape of frequently used libraries, providing an insight on the roles each may cover and when their use is most appropriate.

Working title: Warming up: what will you need going forward with Planetary Computer Hub? Included libraries: PySTAC, PySTAC-client, Pandas, GeoPandas, Xarray, StackSTAC, Dask

[TomAugspurger]

Thanks for opening this up! I'll take a look soon.