swapped await to then for being able to build app

Dockerfile

@@ -0,0 +1,13 @@
+# build stage
+FROM node:lts-alpine as build-stage
+WORKDIR /app
+COPY package*.json ./
+RUN npm install
+COPY . .
+RUN npm run build
+
+# production stage
+FROM nginx:stable-alpine as production-stage
+COPY --from=build-stage /app/dist/spa/ /usr/share/nginx/html
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]