[docs] publish MkDocs site from Forgejo Actions

.forgejo/workflows/docs.yml

@@ -0,0 +1,57 @@
+name: Publish Docs
+
+on:
+  push:
+    branches:
+      - master
+    paths:
+      - ".forgejo/workflows/docs.yml"
+      - "README.md"
+      - "make_docs.sh"
+      - "mkdocs.yml"
+      - "pyproject.toml"
+      - "docs/**"
+      - "meanas/**"
+  workflow_dispatch:
+
+jobs:
+  publish-docs:
+    runs-on: docker
+    container:
+      image: python:3.13-bookworm
+    env:
+      DOCS_SITE_URL: ${{ vars.DOCS_SITE_URL }}
+    steps:
+      - name: Check out the repository
+        uses: https://data.forgejo.org/actions/checkout@v4
+
+      - name: Install build dependencies
+        run: |
+          apt-get update
+          apt-get install -y --no-install-recommends git
+
+      - name: Install docs dependencies
+        run: |
+          pip install -e '.[docs]'
+
+      - name: Build documentation
+        run: |
+          ./make_docs.sh
+
+      - name: Publish docs branch
+        run: |
+          ./scripts/publish_docs_branch.sh site docs-site
+
+      - name: Write job summary
+        run: |
+          {
+            echo "## Published docs"
+            echo
+            echo "- Branch: \`docs-site\`"
+            if [[ -n "${DOCS_SITE_URL:-}" ]]; then
+              echo "- URL: ${DOCS_SITE_URL}"
+            else
+              echo "- URL: set the \`DOCS_SITE_URL\` repository variable to advertise the published site"
+            fi
+            echo "- Recommended repository setting: configure the Wiki tab to point at the published docs URL"
+          } >> "$GITHUB_STEP_SUMMARY"