Update README.md

Add an example of docker-compose.yml that may be useful

README.md

@@ -1,2 +1,38 @@
 # php53-apache-mysql-client-docker
 Docker image with Ubuntu 20.04 with php5.3, apache2 and php5-mysql for discontinued projects that need mysql_connect
+
+Example `docker-compose.yml`
+```
+version: '3'
+services:
+  db:
+    image: mysql
+    command: --default-authentication-plugin=mysql_native_password --collation-server=latin1_general_cs --character-set-server=latin1
+    restart: always
+    environment:
+      MYSQL_ROOT_PASSWORD: example
+    ports:
+      - "3306:3306"
+  php:
+    image: 
+    volumes:
+      - ./path/to/phpapp:/var/www/html
+    links:
+      - "db:mysqldb"
+    ports:
+      - "8080:80"
+    depends_on:
+      - db
+  phpmyadmin:
+    image: phpmyadmin
+    restart: always
+    ports:
+      - 8081:80
+    environment:
+      PMA_HOST: db
+      PMA_USER: root
+      PMA_PASSWORD: example
+      UPLOAD_LIMIT: 1G
+    depends_on:
+      - db
+```