Added GitHub Action

.github/workflows/build-docs.yml

@@ -0,0 +1,50 @@
+name: Build Sphinx Documentation
+
+on:
+  push:
+    branches: [ "*" ]   # Run on every branch
+  workflow_dispatch:
+
+permissions:
+  contents: read
+
+jobs:
+  build-docs:
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v4
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.11"
+          cache: "pip"
+          cache-dependency-path: "requirements.txt"
+
+      - name: Install documentation requirements
+        run: |
+          python -m pip install --upgrade pip
+          pip install -r requirements.txt
+
+      - name: Build HTML documentation
+        run: |
+          make -C docs html
+
+      - name: Create dated ZIP file
+        shell: bash
+        run: |
+          DATE="$(date +%Y%m%d)"
+          ZIPFILE="docs-${DATE}.zip"
+          cd docs/build/html
+          # creates docs/build/docs-YYYYMMDD.zip
+          zip -r "../${ZIPFILE}" .
+
+      - name: Upload ZIP artifact
+        uses: actions/upload-artifact@v4
+        with:
+          name: docs-zip-${{ github.ref_name }}
+          path: docs/build/docs-*.zip
+          if-no-files-found: error
+          retention-days: 7