OpenAstroTracker IMU & GPS Support

This is a GPS and accelerometer holder for the OpenAstroTracker project. It is suitable for the aluminium base and it can be screwed to the 2020 extrusion using M4 screws and T-nuts.

The design is a remix of https://github.com/OpenAstroTech/OpenAstroTracker-Addons/blob/master/DigitalLevel/CAD/Digital%20Level%20Holder%20v7.f3d

Magnetometer is https://www.banggood.com/5Pcs-MAG3110-3-Axis-Digital-Earth-Magnetic-Project-Mat-Field-Geomagnetic-Sensor-Module-I2C-Interface-p-1178808.html
GPS is https://it.aliexpress.com/item/1005001299276444.html

Signals and power supply are routed through an RJ45 plug to carry GND, +5vcc, SDA, SCL, RX, TX. MAG3110 uses GND, 5vcc, SDA, SCL. GPS uses GND, 5vcc, RX, TX