Handle .webp images

Created by: gafemoyano

Hi

I think create-react-app can't handle .webp files right now since it throws the error message:

You may need an appropriate loader to handle this file type. SyntaxError: Unexpected character '�' (1:4)

I wouldn't like to eject just to modify webpack.config so I was wondering if the .webm extension could be added to the file-loader config.

Of course I could just convert the images to jpeg but maybe it's not such an uncommon file format and handling it could improve developer experience