Support for nodemcu32_uart

[jwidess]

Added env for nodemcu32 UART to simplify env setup, #61

[jwidess]

Reviewing this again, it looks like using the -D CANBUS_ENABLED flag alone is invalid and results in the following compilation error,

src/main.cpp: In function 'void setup()':
src/main.cpp:108:22: error: 'vesc' was not declared in this scope
     bleServer->init(&vesc);
                      ^~~~
src/main.cpp:108:22: note: suggested alternative: 'getc'
     bleServer->init(&vesc);
                      ^~~~
                      getc

Due to lines 37-39 in main.cpp and the #ifndef. I'll review this further and see how I was successfully building this for my nodemcu32 using only UART...

[jwidess]

Going to rework this PR to incorporate my new changes and supported boards. Still working on getting the ESP32-C3 working, currently running into a panic on the BleServer...