machine: Add example for Timer class.

machine/example_timer.py

@@ -0,0 +1,11 @@
+import utime
+from machine import Timer
+
+
+t1 = Timer(0, 10)
+t2 = Timer(1, 3)
+t1.callback(lambda t: print(t, "tick1"))
+t2.callback(lambda t: print(t, "tick2"))
+
+utime.sleep(3)
+print("done")