cache: update docs for 1.39
cache: update docs for 1.39

ncw/rclone,yonjah/rclone,seuffert/rclone,yonjah/rclone,seuffert/rclone,ncw/rclone,olihey/rclone,yonjah/rclone,yonjah/rclone,olihey/rclone,B4dM4n/rclone,olihey/rclone,B4dM4n/rclone,seuffert/rclone,ncw/rclone,B4dM4n/rclone,B4dM4n/rclone,ncw/rclone,seuffert/rclone,olihey/rclone