Add Dockerfile for Dokploy deployment

Dockerfile

@@ -0,0 +1,11 @@
+FROM node:20-alpine AS builder
+WORKDIR /app
+COPY package*.json ./
+RUN npm install
+COPY . .
+RUN npm run build
+
+FROM nginx:alpine
+COPY --from=builder /app/dist /usr/share/nginx/html
+COPY nginx.conf /etc/nginx/conf.d/default.conf
+EXPOSE 80