Submodularize D3.js 

This issue should be solved with a production bundler like Rollup or Webpack 

Currently with Snowpack, the d3 "event" module is giving troubles. 
I am attempting to import "event" from "d3-selection" which should work for d3-selection <=@1.4.2
This works on playground sandbox: https://codesandbox.io/s/tender-benz-p5dtn?file=/src/index.js, not on here yet 

