GitLab

Based on 'go help goproxy'.

Updates #33637

Change-Id: I2f3477cfc8f6fb53515604a28a5bc01eb4fe8f48
Reviewed-on: https://go-review.googlesource.com/c/go/+/208777

Reviewed-by: Katie Hockman <katie@golang.org>
Reviewed-by: Bryan C. Mills <bcmills@google.com>