Used github handle

Author: odersky

gsoc/2017.md

@@ -79,7 +79,7 @@ This project is ideal for someone who knows XML basics, and is
 interested to learn enough about aspects of the compiler (either Scala 2.12
 or Dotty) to identify what can be re-used.
 
-Supervised by [Denys Shabalyn](http://github.com/densh)
+Supervised by [@densh](http://github.com/densh)
 
 ### Dotty Documentation Compiler ###