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/examples/i2s/i2s.go

@@ -1,6 +1,5 @@
 // Example using the i2s hardware interface on the Adafruit Circuit Playground Express
 // to read data from the onboard MEMS microphone.
-//
 package main
 
 import (