asgaines: add printing example for Gophercon
asgaines: add printing example for Gophercon

Change-Id: I15e012f3f97dfd7de21534d6629eeaf802b14d10
Reviewed-on: https://go-review.googlesource.com/132347
Run-TryBot: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>
TryBot-Result: Gobot Gobot <66cb808b70d30c07676d5e946fee83fd561249e5@golang.org>
Reviewed-by: Ian Lance Taylor <87e9c6d529889242b7e184afb632328636553ab4@golang.org>

golang/scratch