[Feature Request] timer interrupt callback function

It would be nice if there was a possibility to implement a way to add some own code in the timer interrupt routine. That could be accomplished like it is done in "WInterrupts".

Possible applications:
sampling rotary encoders
sampling tachometer signals
acceleration/deceleration
fading

首先检查现有的 WInterrupts 方案以及 ArduinoCore-API 中的定时器中断 API。确定如何为所列应用提供用户回调，同时保留与硬件无关的 API，然后定义测试或示例，以展示该回调可以被安全地注册和调用。

由索引模型根据 Issue 内容生成。