Auto slide size

[sergeyrudenko]

this package need to update _addSlidesToPresentation method to to use package correctly, i extend constuctor method and inheritance like this
imageFiles.forEach((i) => { var dimentions = sizeOf(i); pptx.setSlideSize(dimentions.width, dimentions.height); pptx.makeNewSlide().addImage(i,{cx: '100%', cy: '100%'}); })
to use this need "npm install --save image-size"
this code create slide with picture dimentions and add image with 100% filling up