feat: add Node.js guestbook skeleton

Dockerfile

@@ -0,0 +1,20 @@
+# Use a lightweight Node image
+FROM node:18-alpine
+
+# Create app directory
+WORKDIR /app
+
+# Copy package.json first to leverage Docker caching
+COPY package.json .
+
+# Install dependencies
+RUN npm install
+
+# Copy the rest of the application files
+COPY . .
+
+# Expose port 3000 (the port your Node app will run on)
+EXPOSE 3000
+
+# Start the server
+CMD ["node", "app.js"]