[chore] improvements on readme testing section.
[chore] improvements on readme testing section.

springload/react-modal,rackt/react-modal,diasbruno/react-modal,springload/react-modal,bluSCALE4/react-modal,seanich/react-modal,reactjs/react-modal,diasbruno/react-modal,seanich/react-modal,reactjs/react-modal,reactjs/react-modal,rackt/react-modal,bluSCALE4/react-modal,bluSCALE4/react-modal,diasbruno/react-modal,springload/react-modal,seanich/react-modal