doc: add tellnes as collaborator

PR-URL: #973
Reviewed-By: Chris Dickinson <christopher.s.dickinson@gmail.com>
Reviewed-By: Evan Lucas <evanlucas@me.com>
Reviewed-By: Brian White <mscdex@mscdex.net>

Author: tellnes

README.md

@@ -280,6 +280,7 @@ information about the governance of the io.js project, see
 * **Sam Roberts** ([@sam-github](https://github.com/sam-github)) <vieuxtech@gmail.com>
 * **Wyatt Preul** ([@geek](https://github.com/geek)) <wpreul@gmail.com>
 * **Brian White** ([@mscdex](https://github.com/mscdex)) <mscdex@mscdex.net>
+* **Christian Vaagland Tellnes** ([@tellnes](https://github.com/tellnes)) <christian@tellnes.com>
 
 Collaborators follow the [COLLABORATOR_GUIDE.md](./COLLABORATOR_GUIDE.md) in
 maintaining the io.js project.