Added information about customizing backends using CSS and JS files
Added information about customizing backends using CSS and JS files

kamilZ/EasyAdminBundle,ogizanagi/EasyAdminBundle,helios-ag/EasyAdminBundle,datagit/EasyAdminBundle,OskarStark/EasyAdminBundle,gabiudrescu/EasyAdminBundle,Seanmcn/EasyAdminBundle,gabiudrescu/EasyAdminBundle,yceruto/EasyAdminBundle,jverdeyen/EasyAdminBundle,OskarStark/EasyAdminBundle,npotier/EasyAdminBundle,ogizanagi/EasyAdminBundle,OskarStark/EasyAdminBundle,alexgt9/EasyAdminBundle,datagit/EasyAdminBundle,ogizanagi/EasyAdminBundle,datagit/EasyAdminBundle,javiereguiluz/EasyAdminBundle,thomasbeaujean/EasyAdminBundle,seydu/EasyAdminBundle,thomasbeaujean/EasyAdminBundle,javiereguiluz/EasyAdminBundle,kamilZ/EasyAdminBundle,kamilZ/EasyAdminBundle,alexgt9/EasyAdminBundle,seydu/EasyAdminBundle,xabbuh/EasyAdminBundle,yceruto/EasyAdminBundle,ogizanagi/EasyAdminBundle,alexgt9/EasyAdminBundle,peterkokot/EasyAdminBundle,seydu/EasyAdminBundle,npotier/EasyAdminBundle,thomasbeaujean/EasyAdminBundle,gabiudrescu/EasyAdminBundle,yceruto/EasyAdminBundle