docs: native report format explained

The output report file path must comply to the following **convention**:

```

<project_root_dir>/reports/<job_name>.<format_name>.<extension>`

<project_root_dir>/reports/<job_name>.<format_name>.<extension>

```

Examples:

- `$PYTHON_PROJECT_DIR/reports/py-coverage.cobertura.xml` is the coverage report produced by the Python template (`py`), using the Cobertura format (XML)

- `reports/docker-sbom-*.cyclonedx.json` is the SBOM report produced by the Docker template, using the CycloneDX format (JSON)

- `reports/docker-hadolint-*.codeclimate.json` is the Hadoling report produced by the Docker template, using the CodeClimate format (JSON)

- `reports/docker-hadolint-*.native.json` is the Hadoling report produced by the Docker template, using the Hadolint native format (JSON)<br/>:warning: `native` should be used as format name when it is the native tool's format

## Dotenv artifacts