Update README.md

Author: phpdave11

README.md

@@ -1,6 +1,6 @@
 php-survey-builder
 
-*php-survey-builder* is a PHP web application that lets you create surveys and collect survey responses. The results can be viewed on charts and exported to CSV. The survey data is stored within a sqlite3 database.
+*php-survey-builder* is a PHP web application that lets you create surveys and collect survey responses. The results can be viewed on charts and exported to CSV. The survey data is stored within a sqlite3 database by default, and can also be stored in a mysql or postgresql database.  Edit config/Database.ini to use mysql or postgresql.
 
 ![screenshot of php-survey-builder](https://raw.github.com/phpdave11/php-survey-builder/master/screenshots/survey_edit.png)