dockerfile improvement

Dockerfile

 # build environment
-FROM quay.io/node:13.12.0 as build
+FROM docker.io/node:13.12.0 as build
 
 # RUN apt-get clean
 # RUN rm -rf /var/lib/apt/lists/*
@@ -19,7 +19,7 @@ RUN npm run build
 
 
 # production environment
-FROM quay.io/nginx:stable-alpine
+FROM docker.io/nginx:stable-alpine
 COPY --from=build /app/build /usr/share/nginx/html
 # new
 COPY nginx/nginx.conf /etc/nginx/conf.d/default.conf