Update readme

Author: r57zone

README.md

@@ -1,5 +1,7 @@
 [![EN](https://user-images.githubusercontent.com/9499881/33184537-7be87e86-d096-11e7-89bb-f3286f752bc6.png)](https://github.com/r57zone/OpenVR-OpenTrack/blob/master/README.md) 
 [![RU](https://user-images.githubusercontent.com/9499881/27683795-5b0fbac6-5cd8-11e7-929c-057833e01fb1.png)](https://github.com/r57zone/OpenVR-OpenTrack/blob/master/README.RU.md) 
+← Choose language | Выберите язык
+
 # OpenVR OpenTrack
 OpenVR / SteamVR driver allowing head tracking with any [OpenTrack](https://github.com/opentrack/opentrack) trackers, for DIY VR headset made of Android smartphone or [HDMI display](http://alii.pub/65dbii), [headset](http://alii.pub/65dct6) and tracker.<br>
 <br>OpenTrack supports the following trackers: FreePie UDP receiver (FreePie IMU for Android), Hatire Arduino or [Razor IMU](https://github.com/Razor-AHRS/razor-9dof-ahrs) ([Arduino](http://ali.pub/1lltzk) + [GY-85](http://ali.pub/1lltk0)), [Oculus DK1](http://ali.pub/1llqtf), Aruco (Paper + [WebCam](http://ali.pub/2k9jf6)) and etc.<br>