Add github workflow to deploy jeykll to pages

Now we're not using the github-pages gem we have to do this "manually".  There's advice in https://jekyllrb.com/docs/continuous-integration/github-actions/ on how to do it, and this is the actions file we'd get if we followed those "click about int he UI" instructions.

.github/workflows/jekyll-github-pages.yml

@@ -0,0 +1,60 @@
+# Sample workflow for building and deploying a Jekyll site to GitHub Pages
+#
+# From: https://github.com/actions/starter-workflows/blob/main/pages/jekyll.yml
+name: Deploy Jekyll site to Pages
+
+on:
+  # Runs on pushes targeting the default branch
+  push:
+    branches: [ruby-3]
+
+  # Allows you to run this workflow manually from the Actions tab
+  workflow_dispatch:
+
+# 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 job
+  build:
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+      - name: Setup Ruby
+        uses: ruby/setup-ruby@v1
+        with:
+          bundler-cache: true
+          cache-version: 0 # Increment this number if you need to re-download cached gems
+      - name: Setup Pages
+        id: pages
+        uses: actions/configure-pages@v4
+      - name: Build with Jekyll
+        # Outputs to the './_site' directory by default
+        run: bundle exec jekyll build --baseurl "${{ steps.pages.outputs.base_path }}"
+        env:
+          JEKYLL_ENV: production
+      - name: Upload artifact
+        # Automatically uploads an artifact from the './_site' directory by default
+        uses: actions/upload-pages-artifact@v3
+
+  # Deployment job
+  deploy:
+    environment:
+      name: github-pages
+      url: ${{ steps.deployment.outputs.page_url }}
+    runs-on: ubuntu-latest
+    needs: build
+    steps:
+      - name: Deploy to GitHub Pages
+        id: deployment
+        uses: actions/deploy-pages@v4