added dockerfile

Dockerfile

@@ -0,0 +1,18 @@
+# build environment
+FROM node:13.12.0-alpine as build
+WORKDIR /app
+ENV PATH /app/node_modules/.bin:$PATH
+COPY package.json ./
+COPY package-lock.json ./
+RUN npm install
+RUN npm ci --silent
+RUN npm install react-scripts@3.4.1 -g --silent
+COPY . ./
+RUN npm run build
+
+# production environment
+FROM nginx:stable-alpine
+COPY --from=build /app/build /usr/share/nginx/html
+COPY --from=build /app/nginx/nginx.conf /etc/nginx/conf.d/default.conf
+EXPOSE 80
+CMD ["nginx", "-g", "daemon off;"]