ci: gh-pages build

Signed-off-by: Alex Chi <iskyzh@gmail.com>

.github/workflows/docs.yaml

@@ -0,0 +1,45 @@
+name: mdbook gh pages
+
+on:
+  push:
+    branches:
+      - main
+
+# Sets permissions of the GITHUB_TOKEN to allow deployment to GitHub Pages
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+# Allow only one concurrent deployment, skipping runs queued between the run in-progress and latest queued.
+# However, do NOT cancel in-progress runs as we want to allow these production deployments to complete.
+concurrency:
+  group: "pages"
+  cancel-in-progress: false
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v2
+      - name: setup mdbook
+        uses: peaceiris/actions-mdbook@v1
+        with:
+          mdbook-version: 'latest'
+      - run: cd docs && mdbook build
+      - name: upload dist
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: docs/book/
+  deploy:
+    runs-on: ubuntu-latest
+    # Add a dependency to the build job
+    needs: build
+    # Deploy to the github-pages environment
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: deploy to gh pages
+        id: deployment
+        uses: actions/deploy-pages@v4