added github publish action, hoping its correct

.github/workflows/build.yml

@@ -0,0 +1,33 @@
+name: Build Eleventy
+
+on:
+    push:
+        branches:
+            - main
+
+jobs:
+    build:
+        runs-on: ubuntu-latest
+
+        strategy:
+            matrix:
+                node-version: [17.x]
+
+        steps:
+            - uses: actions/checkout@v2
+
+            - name: Use Node.js ${{ matrix.node-version }}
+              uses: actions/setup-node@v2
+              with:
+                  node-version: ${{ matrix.node-version }}
+
+            - name: Install dependencies & build
+              run: |
+                  npm ci
+                  npm run build
+
+            - name: Deploy
+              uses: peaceiris/actions-gh-pages@v3.7.3
+              with:
+                  publish_dir: ./www
+                  github_token: ${{ secrets.GITHUB_TOKEN }}