example for `no_std` microcontrollers

[rursprung]

i've just published a small example on the STM32F401RE board (i wrote this a while ago to initially test out the driver & hardware).

would you be interested in having this in your examples folder instead so that you have an example for a no_std environment? the added value over your example is admittedly not that much - it's just a faster copy & paste approach for cortex-m based projects.

[juliangaal]

Sure, good idea. I'll get back to you soon.