Reformat and complete code documentation in Readme.Md

See [EvoMapJS](https://github.com/EvoMapViz/EvoMapJS)/[react](https://github.com/EvoMapViz/EvoMapJS/tree/main/react)/[src](https://github.com/EvoMapViz/EvoMapJS/tree/main/react/src)/Readme.md (https://github.com/EvoMapViz/EvoMapJS/blob/main/react/src/Readme.md)