Additional configuration and information required to stand up portainer instance

[Nate]

There's some additional information/rewording required to standup the portainer instance:

• The SSL host is currently hardcoded as abehrdigital.com in a couple of places in the docker-compose.yml file
• A dummy acme.json file is required for traefik to stand up correctly
• There's a deprecated traefik acme parameter (I don't think this causes any issues though)
• Improve the README where possible

[Nate]

@biskyt I've got a branch with all of these changes but I don't have access to push to the repo so I can't create a PR for it.

[Toby Bisco]

@nathanieloon - if you create a PR from your repo then I can check and merge