added plex_permission service

systems/jeeves/scripts/plex_permission.sh

@@ -0,0 +1,7 @@
+#!/bin/bash
+
+plex_dir="/zfs/storage/plex/"
+
+chown docker-service:users -R "$plex_dir"
+find "$plex_dir" -type f -exec chmod 664 {} \;
+find "$plex_dir" -type d -exec chmod 775 {} \;