Update README.md

Author: csandanov

README.md

@@ -102,6 +102,11 @@ $ docker-compose ps
 
 PHP container has installed drush, [connect to the php container](#accessing-containers) to use drush.
 
+If you want to run drush in the php containter, be sure to open the shell as user 82 (www-data) to avoid access problems in the web server, which is running as user 82, too:
+```bash
+$ docker-compose exec --user 82 php drush
+```
+
 ## Composer
 
 PHP container has installed composer, [connect to the php container](#accessing-containers) to use composer.