add license information to readme
add license information to readme

Emergya/js-rich-marker,criography/js-rich-marker,Infinyty/js-rich-marker,Infinyty/js-rich-marker,tudorpavel/js-rich-marker,criography/js-rich-marker,mikejoyceio/js-rich-marker,googlearchive/js-rich-marker,Jaxwood/js-rich-marker,VQZX/js-rich-marker,Emergya/js-rich-marker,googlearchive/js-rich-marker,mikejoyceio/js-rich-marker,Jaxwood/js-rich-marker,VQZX/js-rich-marker,tudorpavel/js-rich-marker