* Major changes mainly focused on getting type checks working and simplifying code structure.
* Also upgraded to recent version of validator.js from 1.x to 3.x
Fixed issue with manual checks caused by code restructuring.
Allow string `key` to be provided while instantiating `ValidatorError`
docs(README): add new content to docs

Update docs for recent code changes
- Add API section
- Fix spelling mistakes
Release 0.0.3