Generate HTML for MD doc files in GH pages

Based on inputs seen in https://github.com/Shopify/cli/actions/runs/12988959897/job/36221023057

Author: amcaplan

.github/workflows/docs.yml

@@ -34,12 +34,17 @@ jobs:
         uses: ./.github/actions/setup-cli-deps
         with:
           node-version: "22"
-      - name: Build
+      - name: Build TSDoc docs
         run: pnpm nx run-many --all --skip-nx-cache  --target=docs:generate --output-style=stream
+      - name: Build Markdown files into HTML
+        uses: actions/jekyll-build-pages@v1
+        with:
+          source: ./docs
+          destination:	./docs/_site
       - name: Upload artifact
         uses: actions/upload-pages-artifact@v3
         with:
-          path: ./docs
+          path: ./docs/_site
 
   # Deployment job
   deploy: