Add STM32 example

[vpetrigo]

[tlaferriere]

Hi @vpetrigo , just letting you I am currently working on getting this to run on a bluepill (which has an STM32F103CBTx MCU). I will try to make a clean example to include in this repository. There is a little bit of complication with the STM32CubeMX generated code, and I'm using CLion, so the autogenerated CMakeLists.txt may not be very vanilla at first.

Anyway, I'll create a PR for review if this pans out. Have a nice day!

[vpetrigo]

Hello @tlaferriere! That is great, look forward for you PR!