ESLint is only part of the application frontend and only invoked implicitly during build time

* readme files for the repository and the app
* makefile ans the main entry and documentation
* remove create-react-app from client code

src: https://github.com/aamirpinger/todo-app-client-server-kubernetes/commit/93be212a344ea910b0a13f1110975bfdfd306f3a