Document that digitalWrite cannot be called from an interrupt handler

[dirkx]

As digitalWrite() has a CRITICAL section - it cannot be called from an interrupt handler.

May be good to put a warning in the documentation.

[Oleg22805]

Good afternoon, I can’t install your library on Arduino. Link to the Internet page https://mysku.club/blog/diy/105870.html. Library https://github.com/tenbaht/sduino/raw/master/package_sduino_stm8_index.json