BLTouch mount for Tevo Tarantula

This is a remix of **FloridaFishHunter**'s [Tarantula BLTouch Mount](https://www.thingiverse.com/thing:1534021) but it is only using the two back screws, since the two front screws are occupied by the layer fan I am using.

In Marlin I use Bilinear as auto level mode with 3 measurement points, which results in a grid of 3 x 3 = 9 measurement points. I am very happy with this auto leveling sensor and would never go back to manual bed leveling. Can only recommend to get a BLTouch if you do not have one yet.

My sensor offsets in Marlin are the following:

#define SENSOR_LEFT 0
#define SENSOR_RIGHT 28
#define SENSOR_FRONT 2
#define SENSOR_BEHIND 0