v2.0.0 release checklist

[jgravois]

inspiration - https://github.com/zakjan/leaflet-lasso/issues/10

• [x] ensure tree shaking works
• [x] export createCircle()
• [x] fix the test suite
• [x] generate/test a flat ESM build
• [x] ensure ESM code is included in bundles
• [x] test CJS syntax
• [x] fix browser tests
• [x] JSDoc > README API Reference
• [x] are arrow functions going to be problematic somehow? 🤷
• [x] read up on lerna commands for publishing

maybe

• [ ] https://github.com/Esri/terraformer/issues/313
• [ ] https://github.com/Esri/terraformer/issues/321