Add container build action

Dockerfile

@@ -0,0 +1,20 @@
+FROM node:20 AS build
+
+WORKDIR /usr
+COPY package.json ./
+COPY package-lock.json ./
+RUN npm ci
+COPY . ./
+RUN npm run build
+
+FROM node:20
+
+WORKDIR /app
+COPY package.json ./
+COPY package-lock.json ./
+RUN npm ci
+COPY . ./
+COPY --from=build /usr/build /app
+
+EXPOSE 8000
+CMD ["node", "/app"]