added twitter link

readme.txt

@@ -1,6 +1,7 @@
 Grbl - an open source, embedded high performance g-code-parser and CNC milling controller written in optimized C that will run on a straight Arduino.
 
 Documentation: http://dank.bengler.no/-/page/show/5470_grbl
+Dev announcments on twitter @grblcnc: http://twitter.com/grblcnc
 
 Status:
 * Ready for production, but probably rough around the edges still