updates to shaders, readme, and gui

Author: genekogan

README.md

@@ -16,3 +16,7 @@ Click the left and right buttons to scroll through the different shaders, and cl
 
 These are shaders which create an image without any source. Click the left and right buttons to scroll through the shaders.
 
+
+### Shaders GUI
+
+This is a combination of the color shaders and texture shaders with an added user interface to change parameters. Requires [ControlP5 library](http://www.sojamo.de/libraries/controlP5/).