Add example dockerfiles for React app

dockerfile-examples/react/react-app/Dockerfile.correct

@@ -0,0 +1,24 @@
+FROM node:lts-alpine AS base
+
+WORKDIR /app
+
+COPY package.json yarn.lock ./
+
+RUN yarn install
+
+COPY . .
+
+RUN yarn build
+
+FROM nginx:alpine AS serve
+WORKDIR /usr/share/nginx/html
+COPY --from=base /app/dist .
+
+EXPOSE 80
+
+# Demonstrate the difference between CMD and Entrypoint
+# Running image with cmd defined will override the command the container runs
+# Whereas entrypoint, any command you add will be appended
+CMD ["nginx", "-g", "daemon off;"]
+# ENTRYPOINT ["nginx", "-g", "daemon off;"]
+