Update README.md

add information about debug logging

Signed-off-by: Glutamat42 <markus.heck13396@gmx.de>

bitnami/moodle/README.md

@@ -445,6 +445,8 @@ docker-compose logs moodle
 
 You can configure the containers [logging driver](https://docs.docker.com/engine/admin/logging/overview/) using the `--log-driver` option if you wish to consume the container logs differently. In the default configuration docker uses the `json-file` driver.
 
+By default, the logging of debug information is disabled. You can enable it by setting the environment variable `BITNAMI_DEBUG` to `true`.
+
 ## Maintenance
 
 ### Backing up your container