The files types you are looking to add do not have defined buttons to add, but using the file upload you can upload the files of your choosing, just select file from the select list at the top of the window. Here is a list of the allowed file types that you can upload, this list can be edited to include other file types as well if you need to add any.
'7z', 'aiff', 'asf', 'avi', 'bmp', 'csv', 'doc', 'fla', 'flv', 'gif', 'gz', 'gzip', 'jpeg', 'jpg', 'mid', 'mov', 'mp3', 'mp4', 'mpc', 'mpeg', 'mpg', 'ods', 'odt', 'pdf', 'png', 'ppt', 'pxd', 'qt', 'ram', 'rar', 'rm', 'rmi', 'rmvb', 'rtf', 'sdc', 'sitd', 'swf', 'sxc', 'sxw', 'tar', 'tgz', 'tif', 'tiff', 'txt', 'vsd', 'wav', 'wma', 'wmv', 'xls', 'xml', 'zip'