Enable GitHub Pages from within action

This enables GitHub Pages from the action, so that users don’t get this error, and then have to enable it manually themselves:

```bash
Error: Get Pages site failed. Please verify that the repository has Pages enabled and configured to build using GitHub Actions, or consider exploring the `enablement` parameter for this action.
```

.github/workflows/deploy.yml

@@ -27,6 +27,8 @@ jobs:
         uses: actions/checkout@v4
       - name: Setup Pages
         uses: actions/configure-pages@v4
+        with:
+          enablement: true # Enable GitHub Pages if it's not already
       - name: Install dependencies
         run: npm ci
       - name: Build with Eleventy