docs: complete missing GoDocs for main and sub-packages

Signed-off-by: Ron Evans <ron@hybridgroup.com>

drivers.go

@@ -1,5 +1,5 @@
-// Package drivers provides a collection of hardware drivers for devices that
-// can be used together with TinyGo (https://tinygo.org).
+// Package drivers provides a collection of hardware drivers for TinyGo (https://tinygo.org)
+// for devices such as sensors and displays.
 //
 // Here is an example in TinyGo that uses the BMP180 digital barometer:
 //
@@ -9,7 +9,7 @@
 //		"time"
 //		"machine"
 //
-// 		"github.com/tinygo-org/drivers/bmp180"
+// 		"tinygo.org/x/drivers/bmp180"
 // 	)
 //
 // 	func main() {

easystepper/easystepper.go

@@ -1,4 +1,4 @@
-// Simple driver to rotate a 4-wire stepper motor
+// Package easystepper provides a simple driver to rotate a 4-wire stepper motor.
 package easystepper // import "tinygo.org/x/drivers/easystepper"
 
 import (

espat/mqtt/mqtt.go

@@ -1,3 +1,5 @@
+// Package mqtt is intended to provide compatible interfaces with the
+// Paho mqtt library.
 package mqtt
 
 import (