README: Give more detail about `OSC_CONFIG`

README.md

@@ -22,7 +22,15 @@ To use this workflow:
 * set a few CI/CD variables at the project or group level:
   * `GITLAB_CI_USER`, `GITLAB_CI_PASSWORD`: credentials with push access to the
     git repositories to push tags and packaged sources on the `pristine-lfs-source` branch
-  * `OSC_CONFIG`: settings and credentials to access OBS for ABI checks and lintian support
+  * `OSC_CONFIG`: a file variable containing `.oscrc` settings and credentials to access OBS for ABI checks and lintian support
+  ```ini
+  [general]
+  apiurl=https://example.com
+
+  [https://example.com]
+  user=example
+  pass=password123
+  ```
   * `OBS_SERVER`, `OBS_USER`, and `OBS_PASSWORD`: settings and credentials to build the package on OBS,
     further information available [here](https://gitlab.apertis.org/infrastructure/obs-gitlab-runner#required-environment)
 * ensure your git repository follows the [expected structure](https://www.apertis.org/guides/component_structure/)