First try to build docs for github pages.

.github/workflows/deploy-docs.yml

+
+name: deploy-docs
+
+on:
+  push:
+    branches:
+      - 'main'
+
+jobs:
+  deploy-book:
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v2
+
+    # Install dependencies
+    - name: Set up Python 3.7
+      uses: actions/setup-python@v1
+      with:
+        python-version: 3.7
+
+    - name: Install dependencies
+      run: |
+        pip install -U jupyter-book
+    # Build the book
+    - name: Build the docs
+      run: |
+        jupyter-book clean docs
+        jupyter-book build docs
+    - name: Create cname file
+      uses: finnp/create-file-action@master
+      env:
+        FILE_NAME: "./docs/_build/html/CNAME"
+        FILE_DATA: "unhide-docs.helmholtz-metadaten.de"
+
+    # Push the book's HTML to github-pages
+    - name: GitHub Pages action
+      uses: peaceiris/actions-gh-pages@v3.6.1
+      with:
+        github_token: ${{ secrets.GITHUB_TOKEN }}
+        publish_dir: ./docs/_build/html