update readme.md for all samples

Signed-off-by: Anca Iordache <anca.iordache@docker.com>

samples/react-java-mysql/README.md

@@ -0,0 +1,80 @@
+## Compose sample application
+### React application with a NodeJS backend and a MySQL database
+
+Project structure:
+```
+.
+├── backend
+│   ├── Dockerfile
+│   ...
+├── db
+│   └── password.txt
+├── docker-compose.yaml
+├── frontend
+│   ├── ...
+│   └── Dockerfile
+└── README.md
+```
+
+[_docker-compose.yaml_](docker-compose.yaml)
+```
+services:
+  backend:
+    build: backend
+    ...
+  db:
+    image: mysql:5.7
+    ...
+  frontend:
+    build: frontend
+    ports:
+    - 80:9000
+    ...
+```
+The compose file defines an application with three services `frontend`, `backend` and `db`.
+When deploying the application, docker-compose maps port 80 of the frontend service container to port 9000 of the host as specified in the file.
+Make sure port 80 on the host is not already being in use.
+
+## Deploy with docker-compose
+
+```
+$ docker-compose up -d
+Creating network "react-java-mysql_default" with the default driver
+Building backend
+Step 1/10 : FROM maven:3.5-jdk-9 AS build
+...
+Successfully tagged react-java-mysql_frontend:latest
+WARNING: Image for service frontend was built because it did not already exist. To rebuild this image you must use `docker-compose build` or `docker-compose up --build`.
+Creating react-java-mysql_frontend_1 ... done
+Creating react-java-mysql_db_1       ... done
+Creating react-java-mysql_backend_1  ... done
+```
+
+## Expected result
+
+Listing containers must show two containers running and the port mapping as below:
+```
+$ docker ps
+ONTAINER ID        IMAGE                       COMMAND                  CREATED             STATUS              PORTS                  NAMES
+a63dee74d79e        react-java-mysql_backend    "java -Djava.securit…"   39 seconds ago      Up 37 seconds                              react-java-mysql_backend_1
+6a7364c0812e        react-java-mysql_frontend   "docker-entrypoint.s…"   39 seconds ago      Up 33 seconds       0.0.0.0:80->9000/tcp   react-java-mysql_frontend_1
+b176b18fbec4        mysql:5.7                   "docker-entrypoint.s…"   39 seconds ago      Up 37 seconds       3306/tcp, 33060/tcp    react-java-mysql_db_1
+e63be7db7cbc        postgres                    "docker-entrypoint.s…"   2 hours ago         Up 16 minutes       5432/tcp               nginx-golang-postgres_db_1
+```
+
+After the application starts, navigate to `http://localhost:80` in your web browser to get a colorful message.
+```
+My New React App
+```
+
+Stop and remove the containers
+```
+$ docker-compose down
+Stopping react-java-mysql_backend_1  ... done
+Stopping react-java-mysql_frontend_1 ... done
+Stopping react-java-mysql_db_1       ... done
+Removing react-java-mysql_backend_1  ... done
+Removing react-java-mysql_frontend_1 ... done
+Removing react-java-mysql_db_1       ... done
+Removing network react-java-mysql_default
+```