add caveat about map example
add caveat about map example

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