Update Wordpress-MySQL README (#145)

It previously said at the bottom, 
`To remove all Gitea data,`
I changed it from Gitea to Wordpress
`To remove all Wordpress data,`

wordpress-mysql/README.md

@@ -58,7 +58,7 @@ Stop and remove the containers
 $ docker-compose down
 ```
 
-To remove all Gitea data, delete the named volumes by passing the `-v` parameter:
+To remove all Wordpress data, delete the named volumes by passing the `-v` parameter:
 ```
 $ docker-compose down -v
-```
+```