Add Attitude/Artificial Horizon telemetry

[ZZ-Cat]

Overview

Over time, I am adding full telemetry support as modules based on the types of telemetry being added. These are:

• [x] Attitude
• [x] Barometric Altitude
• [x] Battery
• [ ] Flight Modes
• [x] GPS
• [ ] Variometeter

Each module will have its own Issue, Development Branch & Pull Request associated with it, with the end goal of CRSF for Arduino eventually having full telemetry support. Over time, I will make my way through each module.

This Issue is to remind myself to add Attitude telemetry to CRSF for Arduino.

What's needed

Attitude telemetry requires the following values:

• Roll (in radians per second)
• Pitch (in radians per second)
• Yaw (in radians per second)

Additional

Gear list

The gear that I am using for this is as follows:

• Controller: RadioMaster TX16S Max Edition w/EdgeTX version 2.9.0 Nightly
  • Lua script: iNav telemetry widget
• Transmitter Module: RadioMaster Ranger w/ExpressLRS version 3.3.0
• Receiver: RadioMaster RP3 diversity w/ExpressLRS version 3.3.0
• Development board: Adafruit Metro M4 Express

Also...

I am no longer writing my own hardware drivers for each telemetric sensor, because it is better for you to provide your own appropriate sensor modules & their respective hardware drivers. Taking this approach removes the need for me to reinvent the wheel, as there is already a myriad of fantastic sensor drivers out there. All I need to do here, is give you a means of passing data in from your sensors to CRSF for Arduino as telemetry.

[ZZ-Cat]

This will have to sit on the back bench for a little while longer, until I can get #46 merged.
Chores first; awesome shit second.

[ZZ-Cat]

Okay, finally getting around to doing this. =^/.^=