Simplified "Modern Erlang on Debian" wording
Simplified "Modern Erlang on Debian" wording

Recycled wording from https://github.com/rabbitmq/rabbitmq-website/pull/1246 into other relevant section.
rabbitmq/rabbitmq-website,rabbitmq/rabbitmq-website,rabbitmq/rabbitmq-website,rabbitmq/rabbitmq-website,rabbitmq/rabbitmq-website