check permissions for missing volumes and add comment about permissions on examples

examples/tor-hidden-service/docker-compose.yml

@@ -14,6 +14,8 @@ services:
   mywww:
     image: bunkerity/bunkerized-nginx
     restart: always
+    # bunkerized-nginx runs as an unprivileged user with UID/GID 101
+    # don't forget to edit the permissions of the files and folders accordingly
     volumes:
       - ./web-files:/www:ro
     environment: