Add Pages workflow to publish site/ to gh-pages

Author: Wess Cope

.github/workflows/pages.yml

@@ -0,0 +1,39 @@
+name: Pages
+
+# Publish the site/ folder to the gh-pages branch, which GitHub Pages serves
+# (legacy branch mode, with the account-level custom domain). Runs whenever the
+# site under site/ changes.
+
+on:
+  push:
+    branches: [main]
+    paths:
+      - "site/**"
+      - ".github/workflows/pages.yml"
+  workflow_dispatch: {}
+
+permissions:
+  contents: write
+
+concurrency:
+  group: pages
+  cancel-in-progress: true
+
+jobs:
+  publish:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v5
+      - name: Publish site/ to gh-pages
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}
+        run: |
+          set -euo pipefail
+          touch site/.nojekyll
+          cd site
+          git init -q -b gh-pages
+          git config user.name "github-actions[bot]"
+          git config user.email "github-actions[bot]@users.noreply.github.com"
+          git add -A
+          git commit -qm "Publish site from ${GITHUB_SHA}"
+          git push -f "https://x-access-token:${GITHUB_TOKEN}@github.com/${GITHUB_REPOSITORY}.git" gh-pages