Stage 1 development: implement a new C++20 voronoi projection in the file src.projections/a60-carto- projection-voronoi.h using the same carto API as previous.

Base on D3js Vornoi projection

Stage 2 development: variable sized maps with aspect ratio constraint

Abstract any hard-coded map sizes () into variable size map sizes with the same aspect ratio.

Use the a60::carto::frame abstraction for the size of the variable projection, aka

struct area { double x, double y}; from frame.frame_area here: src.projections/a60-carto-frame.h

Stage 3 development: document implementation and usage

Add Voronoi projection documentation

Index to documentation pages: index.md

Summarize the work, methods used, numeric forumlas and other relevant implementation details in docs/voronoi-implementation-notes.md

Explain and illustrate the geometric context, approach, quadrants, in docs/voronoi-context.md

Bibliography, docs/voronoi-bibliography.md