fix(examples): volumes must match (with-nginx-proxy-mariadb-apache)

Signed-off-by: Josh <josh.t.richards@gmail.com>

.examples/docker-compose/with-nginx-proxy/mariadb/apache/compose.yaml

@@ -21,6 +21,7 @@ services:
     restart: always
     volumes:
       - nextcloud:/var/www/html:z
+      # NOTE: The `volumes` config of the `cron` and `app` containers must match
     environment:
       - VIRTUAL_HOST=
       - LETSENCRYPT_HOST=
@@ -45,6 +46,7 @@ services:
     restart: always
     volumes:
       - nextcloud:/var/www/html:z
+      # NOTE: The `volumes` config of the `cron` and `app` containers must match
     entrypoint: /cron.sh
     depends_on:
       - db