Update README.md

Author: ozasadnyy

README.md

@@ -113,7 +113,7 @@ Going to use template? Go on! The only thing we ask - let us know at [*lviv@gdg.
 | [JSday Maceio 2015](http://jsday.com.br) | [DevFest Nordeste 2015](http://2015.devfestne.com.br) | [GDG DevFest Vijayawada 2015](http://devfest.gdg-vijayawada.org) |
 | [Geek Night Recife](http://geeknightrecife.github.io/) | [IO Extended 2016 Madrid ](http://io.gdg.es/) | [AngularCamp](http://angularcamp.org/) |
 | [Mobile Era 2016](http://mobileera.rocks/) | [GDG Francisco Beltrão](http://gdg-fb.github.io) | [Women Techmakers Istanbul 2016](http://2016.wtmistanbul.com) |
-| [Droidcon Paris 2015](http://droidcon.fr) | [Android Makers Paris 2017](http://androidmakers.fr) |
+| [Droidcon Paris 2015](http://droidcon.fr) | [Android Makers Paris 2017](http://androidmakers.fr) | [Heidelberger Symposium 2017](https://heidelberger-symposium.de/) |
 
 
 ### Contributors