Added missing parameters sections

docs/reference/input/on-gesture.md

@@ -2,14 +2,18 @@
 
 Start an [event handler](/reference/event-handler) (part of the
 program that will run when something happens) This handler works when
-you do a **gesture** (like shake, tilt, or drop the micro:bit).
+you do a **gesture** (like shaking the micro:bit).
 
 ```sig
 input.onGesture(Gesture.Shake,() => {
 })
 ```
 
-## Example: random number
+### Parameters
+
+* ``gesture`` means the way you hold or move the micro:bit. This can be `shake`, `logo up`, `logo down`, `screen up`, `screen down`, `tilt left`, `tilt right`, `free fall`, `3g`, or `6g`.
+
+### Example: random number
 
 This program shows a number from `0` to `9` when you shake the micro:bit.