Add `output-values` to terraform-docs

See link for config file:
https://terraform-docs.io/user-guide/configuration/

And how to show output values in the config file:
https://terraform-docs.io/user-guide/configuration/output-values/

Requires running `tofu` to generate an output .json file. Not sure where this functionality sits best at the moment; in the caller or in the reusable.