add copytext info to README. closes #32
add copytext info to README. closes #32

cerealcommas/mashgraphics,wjcjenny/dailygraphics,wjcjenny/dailygraphics,onyxfish/dailygraphics,stlpublicradio/dailygraphics,tophtucker/dailygraphics,nprapps/dailygraphics,nprapps/dailygraphics,stlpublicradio/dailygraphics,nprapps/dailygraphics,eads/dailygraphics,BenHeubl/dailygraphics,tophtucker/dailygraphics,louisstow/dailygraphics,stlpublicradio/dailygraphics,BenHeubl/dailygraphics,swastvedt/dailygraphics,nprapps/dailygraphics,cerealcommas/mashgraphics,abcnews/dailygraphics,cerealcommas/mashgraphics,eads/dailygraphics,wjcjenny/dailygraphics,abcnews/dailygraphics,louisstow/dailygraphics,swastvedt/dailygraphics,stlpublicradio/dailygraphics,louisstow/dailygraphics,swastvedt/dailygraphics,BenHeubl/dailygraphics,eads/dailygraphics,onyxfish/dailygraphics,onyxfish/dailygraphics,abcnews/dailygraphics,abcnews/dailygraphics