ci: forgejo actions workflow to build zensical and deploy to pages

.forgejo/workflows/docs.yml

@@ -0,0 +1,45 @@
+name: Deploy Docs
+on:
+  push:
+    branches:
+      - main
+jobs:
+  deploy:
+    runs-on: docker
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 0
+
+      - uses: actions/setup-python@v5
+        with:
+          python-version: '3.12'
+
+      - run: pip install zensical
+
+      - run: zensical build --clean
+
+      - name: Deploy to pages branch
+        run: |
+          set -e
+          git config user.name "forgejo-actions"
+          git config user.email "forgejo-actions@noreply.local"
+
+          git fetch origin pages
+          git worktree add /tmp/pages-deploy origin/pages
+          cd /tmp/pages-deploy
+
+          git rm -rf --ignore-unmatch .
+          cp -r "$GITHUB_WORKSPACE"/site/* .
+          cp "$GITHUB_WORKSPACE"/site/.[!.]* . 2>/dev/null || true
+
+          git add .
+          if ! git diff --staged --quiet; then
+            git commit -m "deploy: zensical build from ${GITHUB_SHA::7}"
+            git push origin HEAD:pages
+          else
+            echo "No changes to deploy"
+          fi
+        env:
+          GITHUB_WORKSPACE: ${{ github.workspace }}
+          GITHUB_SHA: ${{ github.sha }}