build on ESP32C3 and one pin change

[pljakobs]

Hi VBS,

I know it's been a while but - I have dabbled with a new version of the old controller around the ESP32C3 which I believe is now also supported in sming. Is it possible to extend the automatic builds such that they also build a binary for that cpu (and the extensa based ESP32 as well maybe?) Also, the CLR pin had to move to GPIO18, but I assume that should be a simple change.

pj