add some package docs

device/device.go

@@ -2,6 +2,23 @@
 // Use of this source code is governed under the MIT License
 // that can be found in the LICENSE file.
 
+// Package device provides basic device definition and management.
+//
+// This package offers a definition of a basic device, D, as well as several
+// implementations of D.
+//
+// Users wishing to interact with real devices will find better utility in the
+// "discovery" package, which uses this package to instantiate Remote devices
+// for each discovered device.
+//
+// Mutable is offered to track the pixel state of a given device and generate
+// mutation packets to sync the device to that state.
+//
+// Snapshot can be used to store a (potentially-sampled) pixel state of a
+// given of device.
+//
+// Optional Prometheus monitoring can be enabled by registering on startup
+// (generally init()) via RegisterMonitoring.
 package device
 
 import (

discovery/doc.go

@@ -0,0 +1,12 @@
+// Copyright 2018 Dan Jacques. All rights reserved.
+// Use of this source code is governed under the MIT License
+// that can be found in the LICENSE file.
+
+// Package discovery implements UDP multicast discovery functionality.
+//
+// Most users will want to use a Registry, which keeps track of observed remote
+// devices and instantiates Remote instances for each such device.
+//
+// Transmitter and Listener are low-level discovery primitives that can
+// broadcast discovery packets and receive discovery packets respectively.
+package discovery