fix: Add write permissions to GITHUB_TOKEN in workflow docs-publish.y…

…aml (OpenSTEF#571)

Signed-off-by: Lars Schilders <[email protected]>

.github/workflows/docs-publish.yaml

@@ -11,6 +11,12 @@ on:
 jobs:
   build:
     runs-on: ubuntu-latest
+
+    permissions:
+        # Give the default GITHUB_TOKEN write permission to commit and push the
+        # added or changed files to the repository.
+        contents: write
+
     steps:
     - uses: actions/setup-python@v2
     - uses: actions/checkout@master