Update readme
Update readme

vitkovsky/DFImageManager,Adlai-Holler/DFImageManager,DABSquared/DFImageManager,ichu501/DFImageManager,jsooriah/DFImageManager,holgersindbaek/DFImageManager,hzm0318hzm/DFImageManager,kean/DFImageManager,holgersindbaek/DFImageManager,zhaoguohui/DFImageManager,JeeLiu/DFImageManager,zht415/DFImageManager,arvindhsukumar/DFImageManager