Piwik: Add github link to source code

README.md

@@ -72,7 +72,7 @@ _Web Analytics_
   * [Countly](http://Count.ly) - Real time mobile analytics, crash reporting and push notifications platform ([Source code](https://github.com/countly)) `AGPL` `Javascript`
   * [GoAccess](http://goaccess.io/) - Real-time web log analyzer and interactive viewer that runs in a terminal.
   * [Open Web Analytics](http://www.openwebanalytics.com/) - Google Analytics and Piwik alternative - `GPL` `PHP`
-  * [Piwik](https://piwik.org/) - Leading open-source analytics platform that gives you more than just powerful analytics. - `GPLv3` `PHP`
+  * [Piwik](https://piwik.org/) - Leading open-source analytics platform that gives you more than just powerful analytics. [Source code](https://github.com/piwik/) `GPLv3` `PHP`
   * [Snowplow](http://snowplowanalytics.com/) - Your own digital nervous system. Have every single event, from your websites, mobile apps, desktop applications and server-side systems, stored in your own data warehouse and available to action in real-time. ([Source Code](https://github.com/snowplow/)) `Apache` `Scala`
   * [ThinkUp](https://www.thinkup.com/) - Insights into your social networking activity on Twitter, Facebook, Instagram, and beyond. ([Source code](https://github.com/ThinkUpLLC/ThinkUp)) - `GPL` `PHP`
   * [Webalizer](http://www.webalizer.org/) - Fast web server log file analysis. `GPL` `C`