fix(examples): volumes must match (insecure-postgres-fpm)

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

.examples/docker-compose/insecure/postgres/fpm/compose.yaml

@@ -16,6 +16,7 @@ services:
     restart: always
     volumes:
       - nextcloud:/var/www/html:z
+      # NOTE: The `volumes` config of the `cron` and `app` containers must match
     environment:
       - POSTGRES_HOST=db
       - REDIS_HOST=redis
@@ -32,6 +33,7 @@ services:
       - 127.0.0.1:8080:80
     volumes:
       - nextcloud:/var/www/html:z,ro
+      # NOTE: The `volumes` included here should match those of the `app` container (unless you know what you're doing)
     depends_on:
       - app
 
@@ -40,6 +42,7 @@ 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