v0.2.3

• edgeStep(input, params, seed) adds edges, groups and ports to an input without positions, from its topology alone. docs/JOINT-CORPUS.md tells the rules and the pinned hashes.
• EdgeShape, EdgeStepParams, EDGE_DENSITY and EDGE_STEP_VERSION describe the step.
• LayoutInput has the optional field steps: the stamps of the steps after the generator.
• mulberry32, fnv1a32, stepRandom and randomInt give the seeded random numbers of the generators.