all: format code according to Go 1.19 rules

Go 1.19 started reformatting code in a way that makes it more obvious
how it will be rendered on pkg.go.dev. It gets it almost right, but not
entirely. Therefore, I had to modify some of the comments so that they
are formatted correctly.

src/runtime/runtime_esp32c3.go

@@ -12,6 +12,7 @@ import (
 
 // This is the function called on startup after the flash (IROM/DROM) is
 // initialized and the stack pointer has been set.
+//
 //export main
 func main() {
 	// This initialization configures the following things: