Adjustments in link distance and charge to space out nodes
Added tick function to apply collision detection and bounding box constraints
These are based on a heuristic radius set at 45, because the actual radius is not known until NodeCustomElement has run and done this calc in micro task queue, because bounding box can only be determined after element is appended to DOM
Tweak animations so newly added nodes animate radius in, and edges animate to their target position
Fixes #37 and #8