docs: Broken link in README.md

### Supported output artifacts

The Terraform template supports [job artifacts](https://docs.gitlab.com/ee/ci/pipelines/job_artifacts.html) that your Terraform

The Terraform template supports [job artifacts](https://docs.gitlab.com/ee/ci/jobs/job_artifacts.html) that your Terraform

code may generate and need to propagate to downstream jobs:

* `$TF_OUTPUT_DIR` directory and all contained files are stored as job artifacts.

  Allows to propagate **files**.

* If present, the `terraform.env` file is stored as a [dotenv artifact](https://docs.gitlab.com/ee/ci/pipelines/job_artifacts.html#artifactsreportsdotenv).

* If present, the `terraform.env` file is stored as a [dotenv artifact](https://docs.gitlab.com/ee/ci/yaml/artifacts_reports.html#artifactsreportsdotenv).

  Allows to propagate **environment variables**.

Examples:

#### Implicit Backend configuration support

If you disabled the GitLab-managed Terraform state (by setting `$TF_GITLAB_BACKEND_DISABLED` to `true`),

the template supports an implicit [backend configuration](https://developer.hashicorp.com/terraform/language/settings/backends/configuration#file) mechanism:

the template supports an implicit [backend configuration](https://developer.hashicorp.com/terraform/language/backend#file) mechanism:

1. Looks for a `$environment_type.tfbackend` file (ex: `staging.tfbackend` for staging environment),

2. Fallbacks to `default.tfbackend` file.