add argument of how much to distort

[emitanaka]

As per: https://twitter.com/RHT_ebooks/status/1533358229010272256

This can be thought of as a measure of how much to retain the geographical shape (which may render some hexes to be small) -- if the data value is to be displayed more prominently in the visualisation, you may want to get closer to a tile, where the tiles still retain some spatial orientation relative to each other. If you want to retain the original geographical shape, then it's closer to like the graph rendered for sugarbag.