[Keyboard] remove non-existent method from ploopy documentation (#19957)

Author: ftc

keyboards/ploopyco/trackball/readme.md

@@ -29,20 +29,17 @@ The PCB should indicate which revision this is.
 
 While the defaults are designed so that it can be plugged in and used right away, there are a number of things that you may want to change.  Such as adding DPI control, or to use the ball to scroll while holding a button.   To allow for this sort of control, there is a callback for both the scroll wheel and the mouse sensor. 
 
-The default behavior for this is:
 
 ```c
-void process_wheel_user(report_mouse_t* mouse_report, int16_t h, int16_t v) {
-    mouse_report->h = h;
-    mouse_report->v = v;
-}
-
-void process_mouse_user(report_mouse_t* mouse_report, int16_t x, int16_t y) {
-    mouse_report->x = x;
-    mouse_report->y = y;
+report_mouse_t pointing_device_task_user(report_mouse_t mouse_report){
+    // executed each time the sensor is updated
+    // mouse_report.<attribute> - can be used to access indivdual mouse attributes
+    return mouse_report;
 }
 ```
 
+More information on `report_mouse_t` may be found [here](https://docs.qmk.fm/#/feature_pointing_device?id=manipulating-mouse-reports).
+
 This should allow you to more heavily customize the behavior. 
 
 Alternatively, the `process_wheel` and `process_mouse` functions can both be replaced too, to allow for even more functionality.