Merge pull request #1836 from KonradIT/master

Use markdown lang in the readme.

Author: cmaglie

readme.txt renamed to README.md

@@ -1,32 +1,37 @@
-Arduino is an open-source physical computing platform based on a simple i/o
+Arduino
+========
+
+* Arduino is an open-source physical computing platform based on a simple i/o
 board and a development environment that implements the Processing/Wiring
 language. Arduino can be used to develop stand-alone interactive objects or
 can be connected to software on your computer (e.g. Flash, Processing, MaxMSP).
 The boards can be assembled by hand or purchased preassembled; the open-source
 IDE can be downloaded for free.
 
-For more information, see the website at: http://www.arduino.cc/
+* For more information, see the website at: http://www.arduino.cc/
 or the forums at: http://arduino.cc/forum/
 
-To report a *bug* in the software or to request *a simple enhancement* go to:
+* To report a *bug* in the software or to request *a simple enhancement* go to:
 http://github.com/arduino/Arduino/issues
 
-More complex requests and technical discussion should go on the Arduino Developers
+* More complex requests and technical discussion should go on the Arduino Developers
 mailing list:
 https://groups.google.com/a/arduino.cc/forum/#!forum/developers
 
-If you're interested in modifying or extending the Arduino software, we strongly 
+* If you're interested in modifying or extending the Arduino software, we strongly 
 suggest discussing your ideas on the Developers mailing list *before* starting
 to work on them. That way you can coordinate with the Arduino Team and others,
 giving your work a higher chance of being integrated into the official release
 https://groups.google.com/a/arduino.cc/forum/#!forum/developers
 
 INSTALLATION
+------------
 Detailed instructions are in reference/Guide_Windows.html and
 reference/Guide_MacOSX.html.  For Linux, see the Arduino playground:
 http://www.arduino.cc/playground/Learning/Linux
 
 CREDITS
+--------
 Arduino is an open source project, supported by many.
 
 The Arduino team is composed of Massimo Banzi, David Cuartielles, Tom Igoe,