Guide on interoperability with C

[metehus]

The rust ecossystem of the espressif chips are very helpful, but there are still a lot of libraries needed that are only on C environments, and porting it would take a lot of effort. That's why I think inlcuding C libraries on the rust code is a very needed thing, but aslo very hard. I am trying to do that using bindgen and embuild, but no success yet. I would love to see a guide or more material about this topic