update readme

README.md

@@ -53,6 +53,7 @@ The next image shows a New Relic dashboard with some of the Gitlab metrics you
 | `GLAB_PROJECT_VISIBILITIES` | Project visibilities (public,private,internal) | False | List* | private |
 | `GLAB_DORA_METRICS` | Export DORA metrics, requires Gitlab ULTIMATE | True | Bool | False |
 | `GLAB_EXPORT_PATHS` | Project paths aka namespace full_path to obtain data from | False | List* | None if running as standalone or CI_PROJECT_ROOT_NAMESPACE if running as pipeline schedule|
+| `GLAB_RUNNERS_INSTANCE` | Obtain runners from gitlab instance instead of project only  | True | String | |
 | `GLAB_EXPORT_PROJECTS_REGEX` | Regex to match project names against “.*” for all | False | Boolean | None |
 | `GLAB_EXPORT_PATHS_ALL` | When True ignore GLAB_EXPORT_PATHS variable and export projects matching GLAB_EXPORT_PROJECTS_REGEX in any groups or subgroups| True |  Boolean | False |
 | `GLAB_CONVERT_TO_TIMESTAMP` | converts datetime to timestamp | True | Boolean | False |