Merge pull request #2 from fullstack-devops/bugfix/some-docu

add  env variables docu

Author: eksrha

README.md

@@ -1,2 +1,22 @@
 # github-runner-base
-Base Image for github runner images in repo @fullstack-devops/github-runner
+Base Image for github runner images in repo @fullstack-devops/github-runner. Can also be used as standalone image.
+
+---
+
+## Environmental variables
+
+### Required environmental variables
+
+| Variable          | Type   | Description                                                                                                       |
+|-------------------|--------|-------------------------------------------------------------------------------------------------------------------|
+| `GH_ORGANIZATION` | string | Points to the GitHub Organisation where the runner should be installed                                            |
+| `GH_ACCESS_TOKEN` | string | Developer Token vor the GitHub Organisation<br> This Token can be personal and is onlv needed during installation |
+
+### Optional environmental variables
+
+For the helm values see the [values.yaml](helm/values.yaml), section `envValues`
+
+| Variable     | Type   | Default                  | Description                                                          |
+|--------------|--------|--------------------------|----------------------------------------------------------------------|
+| `GH_URL`     | string | `https://github.com`     | For GitHub Enterprise support                                        |
+| `GH_API_URL` | string | `https://api.github.com` | For GitHub Enterprise support eg.: `https://git.example.com/api/v3/` |