message: Readme update and checking `type` option presence
diff: @@ -997,7 +997,7 @@ var PptxGenJS = function(){
  strSlideXml += ' </p:nvPicPr>';
  strSlideXml += '<p:blipFill>';
  strSlideXml += ' <a:blip r:embed="rId' + slideItemObj.imageRid + '" cstate="print"/>';
  - if (sizing) {
  + if (sizing && sizing.type) {
  var boxW = sizing.w ? getSmartParseNumber(sizing.w, 'X') : cx,
  boxH = sizing.h ? getSmartParseNumber(sizing.h, 'Y') : cy,
  boxX = getSmartParseNumber(sizing.x || 0, 'X'),
  