add quick usage example

README.md

@@ -4,6 +4,13 @@ Also, please don't submit bug reports to the links on this page, those will dire
 
 The purpose of this is to experiment with the RTL code and other things, and is purely for academic research into the inner workings of DSD. Basically, its for me to poke around with and see what I can manage to break.
 
+# Example Usage
+padsp -m dsdfme -- ./dsd -fp -i rtl -o /dev/dsp -c 851.8M -d ./MBE/ -P -2 -D 1 -G 36
+
+-i rtl to use rtlsdr 
+-P set PPM error
+-D set device index number
+-G set device gain (0-49 typical)
 
 ## License
 Copyright (C) 2010 DSD Author