chore: generate and maintain in-repo module documentation

[displague]

The generate-terraform-docs workflow will use the terraform-docs/gh-actions action to generate Terraform documentation based on the module's provider requirements, variables, and outputs.

The peter-evans/create-pull-request action will open new pull requests to ensure that the README.md of each module, including the root module, includes this generated content and that the content stays up to date as changes are made to the project.

An example of the output is here: https://github.com/equinix-labs/terraform-equinix-metal-k3s?tab=readme-ov-file#terraform-module-documentation

[devenkulkarni]

I reviewed the changes and do not see anything blocking our operation with the repo...
The PR includes a github actions workflow and needs the repo CI env var and permissions hence our existing github action workflow is failing with CI errors.

@dnoland1 I think we can approve and merge the PR.

[displague]

@devenkulkarni I fixed the merge conflict in README.md. Who can merge this?

[glovecchi0]

Given the error in the CI phase, it may be necessary to add the environment variables as done for the other pipeline.

        env:
          METAL_AUTH_TOKEN: ${{ secrets.metal_auth_token }}
          TF_VAR_project_name: Harvester Labs
          TF_VAR_api_key: ${{ secrets.metal_auth_token }}

cc: @displague

[displague]

If https://github.com/rancherlabs/terraform-harvester-equinix/blob/main/variables.tf#L21 was true (make the Harvester Demo project by default), the only required variables would be Metal API tokens.

[glovecchi0]

If https://github.com/rancherlabs/terraform-harvester-equinix/blob/main/variables.tf#L21 was true (make the Harvester Demo project by default), the only required variables would be Metal API tokens.

Good point! Please, open an issue to set the default value to true.