Add example

example/shiftOut_example.lua

@@ -0,0 +1,14 @@
+require("shiftOut")
+
+LatchPin = 4
+DataPin = 2
+ClockPin = 3
+
+register = shiftOut:new(LatchPin, DataPin, ClockPin)
+
+register:shiftOut("11000000") -- string value
+register:shiftOut(192) -- decimal digit value
+
+-- By default bit order is MSBFIRST, but you can change it to LSBFIRST
+register:shiftOut("11000000", LSBFIRST)
+register:shiftOut(192, MSBFIRST)