Inconsistency regarding display_config in Readme

Currently in `README.md` says

> - `resources/display_config.ron`
> Contains the window configuration (size, title).

However there is no `resources` folder. I'd assume it should be referring to the `config` folder instead.
Further more, the book states the project should contain a `config/display.ron`.

I'm new to the project and don't know what source is correct. Could I get some clarification, so that I can create a pull request?