Add Athens to the Chapter List (#502)

README.md

@@ -11,6 +11,7 @@ If you enjoy the papers, perhaps stop by a local chapter meetup and join in on t
 Here are our official chapters. Let us know if you are interested in [starting one](https://github.com/papers-we-love/papers-we-love/wiki/Creating-a-PWL-chapter) in your city!
 
 * [Amsterdam](http://www.meetup.com/papers-we-love-amsterdam/)
+* [Athens](https://www.meetup.com/Papers-We-Love-Athens)
 * [Bangalore](http://www.meetup.com/Papers-we-love-Bangalore/)
 * [Barcelona](https://www.meetup.com/papers-we-love-bcn/)
 * [Belfast](http://www.meetup.com/Papers-We-Love-Belfast/)