updated readme to describe an IE desktop fallback
updated readme to describe an IE desktop fallback
samiadelgado/picturefill,albell/picturefill,scottjehl/picturefill,demateu/picturefill,yufi113/picturefill,guardian/picturefill,mcanthony/picturefill,patrickkettner/picturefill,albell/picturefill,patrickkettner/picturefill,nucliweb/picturefill,yubin-huang/picturefill,yufi113/picturefill,rockmandew/picturefill,rockmandew/picturefill,chrismcandrew/picturefill,guardian/picturefill,iancrowther/picturefill,purposeindustries/picturefill,ddeveloperr/picturefill,demateu/picturefill,chrismcandrew/picturefill,mcanthony/picturefill,jansepar/picturefill,yubin-huang/picturefill,ddeveloperr/picturefill,purposeindustries/picturefill,footiealf/picturefill,iancrowther/picturefill,footiealf/picturefill,scottjehl/picturefill,samiadelgado/picturefill