Pointed to incorrect file in the README

[stencilman]

Great tutorials, helps a lot, thanks for making it public!

Small comment:
You say "In simple_example.lua, there is a line containing the word "UNCOMMENT" illustrating how to view a digit from the train/test sets."
Actually, it is practical3.lua where the word UNCOMMENT occurs and that is where the code to visualize the data exists.