Update readme

README.md

@@ -79,7 +79,7 @@ The structure of this document is organized as follows:
 
 # Part 3: Setting up the target device
 
-## Set up the target with PYNQ-DPU image
+## Set up the target with PYNQ image
   + Download the PYNQ v2.5 board image from http://www.pynq.io/board.html
   + Burn the .img file to a blank SD card.  The example command below uses ``dd``, but feel free to use your favorite disk imaging tool.