Update docs to match h3-py v4.x

[ajfriend]

Update the cells <> polygon functions in the h3geo.org docs to match h3-py v4.x.

Update: Also rework the h3geo.org docs so that language-agnostic function descriptions are given first, and language-specific details are given below the language tabs.

This also fixes some bugs in the docs that I found along the way.

[coveralls]

coverage: 98.783% (+0.001%) from 98.782%
when pulling f5cd869 on aj/py4_docs
into 09d96cd on master.

[ajfriend]

One issue I see in the docs, however, is that the text below is shown for all the languages, but may not apply to all equally:

polygonToCells takes a given GeoJSON-like data structure and preallocated, zeroed memory, and fills it with the hexagons that are contained by the GeoJSON-like data structure.

Containment is determined by the cells' centroids. A partitioning using the GeoJSON-like data structure, where polygons cover an area without overlap, will result in a partitioning in the H3 grid, where cells cover the same area without overlap.

The Python function does not take a GeoJSON-like data structure, for example.

Would it make sense to have some of the text be language-specific?

[isaacbrodsky]

One issue I see in the docs, however, is that the text below is shown for all the languages, but may not apply to all equally:

polygonToCells takes a given GeoJSON-like data structure and preallocated, zeroed memory, and fills it with the hexagons that are contained by the GeoJSON-like data structure.
Containment is determined by the cells' centroids. A partitioning using the GeoJSON-like data structure, where polygons cover an area without overlap, will result in a partitioning in the H3 grid, where cells cover the same area without overlap.

The Python function does not take a GeoJSON-like data structure, for example.

Would it make sense to have some of the text be language-specific?

Maybe it should be written more generally, and the parts specific to the C api placed under the appropriate tab. Preallocated memory does not apply to any of the bindings.

[ajfriend]

[ajfriend]

Maybe it should be written more generally, and the parts specific to the C api placed under the appropriate tab. Preallocated memory does not apply to any of the bindings.

I took a stab as an example. Let me know what you think!

[ajfriend]

I don't think we explain the difference between "centroid" and "center" in the docs, but we should. The old description here makes a distinction: e3a48ad

[ajfriend]

This is ready for review. I made a bunch of changes, so I'll re-request.