feat: add manifest support

[tmlye]

• Add manifest support and make it the path to the manifest the default argument
• Remove --image, --port and --env args as they are in the manifest
• Refactor to make greater use of match and move new service creation to a separate method
• Fix a bug where not having a default org in the config file caused a panic. Centralized getting org name code

Example manifest:

environment: hi
service:
  name: bla3
  image: nginx
  container_port: 80

[bittermandel]

Shouldn't the manifest be the default method?

[tmlye]

Shouldn't the manifest be the default method?

Agree, updated

[tmlye]

@bittermandel re-review please