Updated example for TypeScript + React

[dv297]

I'd be interested in updating the TypeScript + React example to match some more modern standards, and I have an initial draft hosted here.

https://github.com/dv297/typescript-react-todo

All of the browser tests are passing, code was formatted using Prettier.

My only concern is that it might be missing the point of TodoMvc, as all I've done is implemented the application idiomatically through TypeScript and React using useState. Many of the React examples I've seen here have used a todoModel.js, which seemed a little weird to me for idiomatic React. I did this as a learning example, so if this wouldn't match the philosophy, no harm, no foul, and feel free to close this issue =)

[FadySamirSadek]

Please open a PR