Touch Mi - I3 Mega clip support

This support can be clipped to the hot end (no glue, screw or anything).
Sensor can be plugged to Sensor pin of the motherboard (PIN 11).

Sensor is called "Touch Mi" and is available at hotends.fr store. (I'm not affiliated with them).

Marlin 1.1.8 can be used to enable auto bed levelling.

Offset between nozzle and sensor is around 4cmx4cm. This prevent full bed probing but is enough to perform a proper linear leveling.

You will need one M3 screw and nut (16mm I think).

TODO : use the magnet to activate the sensor automatically. Sensor is for the time being released manually and is put in a safe position after the end of the G29.