template: use Go font

These fonts are available under the usual license at
	golang.org/x/image/font/gofont

Change-Id: Ifeb5c3478bc6752b75f1d1128d05141d7bc4a45e
Reviewed-on: https://go-review.googlesource.com/33259
Reviewed-by: Rob Pike <[email protected]>

Author: adg