fix: update readme to include psql

README.md

@@ -5,11 +5,12 @@
 [![Dependency Status](https://david-dm.org/nodebb/nodebb.svg?path=install)](https://david-dm.org/nodebb/nodebb?path=install)
 [![Code Climate](https://codeclimate.com/github/NodeBB/NodeBB/badges/gpa.svg)](https://codeclimate.com/github/NodeBB/NodeBB)
 
-[**NodeBB Forum Software**](https://nodebb.org) is powered by Node.js and built on either a Redis or MongoDB database. It utilizes web sockets for instant interactions and real-time notifications. NodeBB has many modern features out of the box such as social network integration and streaming discussions, while still making sure to be compatible with older browsers.
+[**NodeBB Forum Software**](https://nodebb.org) is powered by Node.js and supports either Redis, MongoDB, or a PostgreSQL database. It utilizes web sockets for instant interactions and real-time notifications. NodeBB has many modern features out of the box such as social network integration and streaming discussions, while still making sure to be compatible with older browsers.
 
 Additional functionality is enabled through the use of third-party plugins.
 
-* [Demo & Meta Discussion](http://community.nodebb.org)
+* [Demo](https://try.nodebb.org)
+* [Developer Community](http://community.nodebb.org)
 * [Documentation & Installation Instructions](http://docs.nodebb.org)
 * [Help translate NodeBB](https://www.transifex.com/projects/p/nodebb/)
 * [NodeBB Blog](http://blog.nodebb.org)