Z sensor mount locators for TronXY P802MA

To add to my series of printer improvements, I wanted to make sure I could keep my z offset well-calibrated.

The stock bracket and auto leveling sensor on the P802MA has adjustment slots for mounting the sensor bracket and on the sensor itself. These three pairs of slots make it easy for the sensor to move out of place in my experience.

These slots are useful for adjustment, but once you have a well-adjusted machine you can just measure the position of the sensor and the bracket and make