Adjust rabbitmq configuration recommendation to use a file above the heinous environment variable

rabbitmq/content.md

@@ -163,11 +163,9 @@ Example `enabled_plugins`
 
 ### Additional Configuration
 
-If additional configuration is required, it is recommended to use the `RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS` environment variable, whose syntax is described [in section 7.8 ("Configuring an Application") of the Erlang OTP Design Principles User's Guide](http://erlang.org/doc/design_principles/applications.html#id81887) (the appropriate value for `-ApplName` is `-rabbit`).
+If additional configuration is required, it is recommended to supply an appropriate `/etc/rabbitmq/rabbitmq.conf` file (see [the "Configuration File(s)" section of the RabbitMQ documentation for more details](https://www.rabbitmq.com/configure.html#configuration-files)), for example via bind-mount, [Docker Configs](https://docs.docker.com/engine/swarm/configs/), or a short `Dockerfile` with a `COPY` instruction.
 
-For example, configuring [`log_levels`](https://www.rabbitmq.com/configure.html#config-items) would look something like `-e RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS="-rabbit log_levels [{connection,error}]"`.
-
-Additional configuration keys would be specified as a list. For example, configuring both [`log_levels`](https://www.rabbitmq.com/configure.html#config-items) and [`auth_backends`](https://www.rabbitmq.com/ldap.html#overview) would look something like `-e RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS="-rabbit log_levels [{connection,error}] auth_backends [rabbit_auth_backend_ldap]"`.
+Alternatively, it is possible to use the `RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS` environment variable, whose syntax is described [in section 7.8 ("Configuring an Application") of the Erlang OTP Design Principles User's Guide](http://erlang.org/doc/design_principles/applications.html#id81887) (the appropriate value for `-ApplName` is `-rabbit`), but this method is much harder to get right than the configuration file format suggested above. For example, configuring [`log_levels`](https://www.rabbitmq.com/configure.html#config-items) would look something like `-e RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS="-rabbit log_levels [{connection,error}]"`. Additional configuration keys would be specified as a list. For example, configuring both [`log_levels`](https://www.rabbitmq.com/configure.html#config-items) and [`auth_backends`](https://www.rabbitmq.com/ldap.html#overview) would look something like `-e RABBITMQ_SERVER_ADDITIONAL_ERL_ARGS="-rabbit log_levels [{connection,error}] auth_backends [rabbit_auth_backend_ldap]"`.
 
 ## Connecting to the daemon