Add doc links

README.md

@@ -34,3 +34,10 @@ Installing the primary gousb package is really easy:
 There is also a `usbid` package that will not be installed by default by this command, but which provides useful information including the human-readable vendor and product codes for detected hardware.  It's not installed by default and not linked into the `usb` package by default because it adds ~400kb to the resulting binary.  If you want both, they can be installed thus:
 
     go get -v github.com/kylelemons.net/gousb/usb{,id}
+
+Documentation
+=============
+The documentation can be viewed via local godoc or via Gary Burd's excellent [GoPkgDoc](http://gopkgdoc.appspot.com):
+
+- [usb](http://gopkgdoc.appspot.com/pkg/github.com/kylelemons/gousb/usb)
+- [usbid](http://gopkgdoc.appspot.com/pkg/github.com/kylelemons/gousb/usbid)