Encourage people towards the various help forums as a first port of
call. Better sign-posting will reduce the incidence or questions being
asked in the issue tracker that should otherwise be handled elsewhere,
thereby keeping the issue tracker email traffic more focussed.

Change-Id: I13b2e498d88be010fca421067ae6fb579a46d6b7
Reviewed-on: https://go-review.googlesource.com/34250Reviewed-by: Brad Fitzpatrick <bradfitz@golang.org>