* Add speed heading to driver
Added NAV-VELNED messages to driver, allowing speed and heading info on the main web page and JSON messages. Probably could be optimized; mostly another exercise in copy/paste
* wrap velocity code in #define USE_GPS_VELOCITY
Code space increases by 0k4, not sure about RAM (don't know how to measure). But added a struct with 320 bits, so maybe 40 bytes?
* Add documentation up top
---------
Co-authored-by: Theo Arends <11044339+arendst@users.noreply.github.com>
pkkrusty
Barbudor
Theo Arends