v4.0.0 - Type all the things!

• convert to typescript
  • BREAKING: the src/ folder is no longer JavaScript but TypeScript, so any project importing directly from there will now need to import from dist/.
• fix: converting to TypeScript revealed that the clone() method did not even work (it tried to call a clone() method on a number)
• move classes and shader into separate files
• rename MeshLine to MeshLineGeometry, and a new MeshLine class that extends from THREE.Mesh and provides the raycast method for mesh lines. This aligns better with three.js patterns.
  • BREAKING: Replace all usages of MeshLine with MeshLineGeometry, then replace usages of THREE.Mesh with MeshLine for any meshes that use MeshLineGeometry. If you were using MeshLineRaycast, instead use the new MeshLine class in place of THREE.Mesh then you're all set for raycasting.
• feat: finish fog support. birds demo now has fog.
• demos now published to https://docs.lume.io/three-meshline/