Update CI status and configuration

.github/workflows/node.js.yml

@@ -0,0 +1,23 @@
+name: Node.js CI
+
+on: [push]
+
+jobs:
+  build:
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v4
+      - name: Use Node.js
+        uses: actions/setup-node@v4
+        with:
+          node-version: '20.x'
+      - run: npm install
+      - run: npm run build --if-present
+      - name: Archive production artifacts
+        uses: actions/upload-artifact@v4
+        with:
+          name: dist_${{ github.sha }}
+          path: |
+            dist

README.md

@@ -1,5 +1,7 @@
 ## Introduction
 
+[![Node.js CI](https://github.com/HoshinoKoji/js-exform/actions/workflows/node.js.yml/badge.svg)](https://github.com/HoshinoKoji/js-exform/actions/workflows/node.js.yml)
+
 This project is to develop a Vue 3 single page questionnaire application to be embedded in online psychology experiments. Demo pages are hosted to show how it looks like:
 - [Standard](https://js-exform.pages.dev/demo)
 - [Dark mode](https://js-exform.pages.dev/demo-dark)