fetch pxt-microbit v2.2.30 (#102)

* undo buttonEvent

* fetch microbit v2.2.30

Co-authored-by: Amerlander <gitkraken@juriwolf.de>

docs/examples/rando.md

@@ -4,6 +4,6 @@ Generate a random coordinate and display it on the LED screen.
 
 ```blocks
 basic.forever(() => {
-    led.toggle(Math.randomRange(0, 5), Math.randomRange(0, 5))
+    led.toggle(Math.randomRange(0, 4), Math.randomRange(0, 4))
 })
 ```