docs: publish MkDocs site

.github/workflows/pages.yml

@@ -0,0 +1,61 @@
+name: Docs
+
+on:
+  push:
+    branches:
+      - main
+    paths:
+      - ".github/workflows/pages.yml"
+      - "docs/requirements.txt"
+      - "mkdocs.yml"
+      - "docs/site/**"
+  workflow_dispatch:
+
+permissions:
+  contents: read
+  pages: write
+  id-token: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: false
+
+jobs:
+  build:
+    name: Build static docs
+    runs-on: ubuntu-latest
+    steps:
+      - name: Check out repo
+        uses: actions/checkout@v4
+
+      - name: Configure Pages
+        uses: actions/configure-pages@v5
+
+      - name: Set up Python
+        uses: actions/setup-python@v5
+        with:
+          python-version: "3.13"
+
+      - name: Install docs dependencies
+        run: python -m pip install -r docs/requirements.txt
+
+      - name: Build docs site
+        run: mkdocs build --strict
+
+      - name: Upload Pages artifact
+        uses: actions/upload-pages-artifact@v3
+        with:
+          path: _site
+
+  deploy:
+    name: Deploy to GitHub Pages
+    if: github.ref == 'refs/heads/main'
+    needs: build
+    runs-on: ubuntu-latest
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    steps:
+      - name: Deploy Pages artifact
+        id: deployment
+        uses: actions/deploy-pages@v4

.gitignore

@@ -3,6 +3,7 @@
 
 # Local scratch output
 /tmp/
+/_site/
 
 # Vouch output when dogfooding this repo itself
 /.vouch/build/