see also the Dendrogram Small Data and react-app examples.
D3’s cluster layout produces node-link diagrams with leaf nodes at equal depth. These are less compact than tidy trees, but are useful for dendrograms, hierarchical clustering and phylogenetic trees. See also the radial variant.`
inspired by https://observablehq.com/@d3/cluster-dendrogram
https://cdnjs.cloudflare.com/ajax/libs/d3/5.9.2/d3.min.js