Improve readme

Signed-off-by: Michal Čihař <michal@cihar.com>

README.md

@@ -1,25 +1,26 @@
-# alpine linux + php + phpmyadmin
+# Official phpMyAdmin Docker image
 
-Run PHPMyAdmin with alpine + php built in web server
+Run phpMyAdmin with Alpine and PHP built in web server.
 
 [![Build Status](https://travis-ci.org/phpmyadmin/docker.svg?branch=master)](https://travis-ci.org/phpmyadmin/docker)
 
 
 ## Usage
 
-First， you need to run mysql in docker, and this image need link a running mysql instance container
+First you need to run MySQL or MariaDB server in Docker, and this image need
+link a running mysql instance container:
 
 ```
 docker run --name myadmin -d --link mysql_db_server:db -p 8080:8080 phpmyadmin/phpmyadmin
 ```
 
 Then open browser, visit http://***.***.host.ip:8080
 
-You will see the phpmyadmin login page
+You will see the phpMyAdmin login page.
 
 ## Usage with arbitrary server
 
-You can use arbitrary servers by adding ENV variable PMA_ARBITRARY=1 to the startup command:
+You can use arbitrary servers by adding ENV variable PMA\_ARBITRARY=1 to the startup command:
 
 ```
 docker run --name myadmin -d --link mysql_db_server:db -p 8080:8080 -e PMA_ARBITRARY=1 phpmyadmin/phpmyadmin