Merge pull request #425 from hx2A/addlink

add link to user functions page

Author: hx2A

py5_docs/Reference/api_en/Sketch.txt

@@ -7,7 +7,7 @@ processing_name = PApplet
 @@ description
 Core py5 class for leveraging py5's functionality. This is analogous to the PApplet class in Processing. Launch the Sketch with the [](sketch_run_sketch) method.
 
-The core functions to be implemented by the py5 coder are `settings`, `setup`, and `draw`. The first two will be run once at Sketch initialization and the third will be run in an animation thread, once per frame. The following event functions are also supported:
+The core functions to be implemented by the py5 coder are `setup` and `draw`. The first will be run once at Sketch initialization and the second will be run in an animation thread, once per frame. The following event functions are also supported:
 
 * `exiting`
 * `key_pressed`
@@ -22,7 +22,10 @@ The core functions to be implemented by the py5 coder are `settings`, `setup`, a
 * `mouse_released`
 * `mouse_wheel`
 * `movie_event`
+* `predraw_update`
 * `post_draw`
 * `pre_draw`
 
-When coding in class mode, all of the above functions should be class methods. When coding in module mode or imported mode, the above functions should be stand-alone functions available in the local namespace in which [](sketch_run_sketch) was called.
+When coding in class mode, all of the above functions should be instance methods. When coding in module mode or imported mode, the above functions should be stand-alone functions available in the local namespace in which [](sketch_run_sketch) was called.
+
+For more information, look at the online ["User Functions"](/content/user_functions) documentation.