Made instructions more clear.

Not sure what happened to my last commit so this includes that one + reordering the steps.

README.md

 Install the arduino software IDE/toolset v23 (Some configurations also work with 1.x.x)
    http://www.arduino.cc/en/Main/Software
 
+Download the Marlin firmware
+   https://github.com/ErikZalm/Marlin/tree/Marlin_v1
+   Use the "Download Zip" button on the right.
+
 For gen6/gen7 and sanguinololu the Sanguino directory in the Marlin dir needs to be copied to the arduino environment.
   copy ArduinoAddons\Arduino_x.x.x\sanguino <arduino home>\hardware\Sanguino
 
-Copy the Marlin firmware
-   https://github.com/ErikZalm/Marlin/tree/Marlin_v1
-   (Use the download button)
-
 Start the arduino IDE.
 Select Tools -> Board -> Arduino Mega 2560    or your microcontroller
 Select the correct serial port in Tools ->Serial Port