Various documentation updates needed

[glennmatthews]

Celery/Redis inconsistencies:

• https://github.com/networktocode-llc/nautobot-docker-compose/blob/main/docs/img/container_stack.png shows the RQ worker, but doesn't show the Celery worker
  • Also, it shows two separate containers for Redis, but the docker-compose.yml only defines a single combined Redis container?
• The docker container ls output in README.md similarly doesn't include nautobot_celery_worker but does include two separate Redis containers

https://github.com/networktocode-llc/nautobot-docker-compose/blob/main/docs/create_ssl_cert.md - still has just a placeholder for Let's Encrypt - do we need to add this before release?