XEdge NAS mirror upload tree

Upload these directories to the mirror:

  dist/nas-mirror/synology/  ->  https://ts-mirror.xedge.cc/stable/synology/
  dist/nas-mirror/qnap/      ->  https://ts-mirror.xedge.cc/stable/qnap/

The package files are hardlinked from dist when possible, so this tree
does not normally duplicate package data on disk.