cmd/gerritbot: remind people to publish their draft comments

Update golang/go#18517

Change-Id: Ia970d648b85cd75831ee0c6969762752e9b49289
Reviewed-on: https://go-review.googlesource.com/93355
Reviewed-by: Brad Fitzpatrick <[email protected]>

Author: andybons

Diff for: cmd/gerritbot/gerritbot.go

@@ -390,7 +390,10 @@ func (b *bot) processPullRequest(ctx context.Context, pr *github.PullRequest) er
 		if m.Author.Email() == cl.Owner().Email() {
 			continue
 		}
-		msg := fmt.Sprintf("%s has posted review comments at [golang.org/cl/%d](https://go-review.googlesource.com/c/%s/+/%d#message-%s).",
+		msg := fmt.Sprintf(`%s has posted review comments at [golang.org/cl/%d](https://go-review.googlesource.com/c/%s/+/%d#message-%s).
+
+After addressing review feedback, remember to
+[publish your drafts](https://github.com/golang/go/wiki/GerritBot#i-left-a-reply-to-a-comment-in-gerrit-but-no-one-but-me-can-see-it)!`,
 			m.Author.Name(), cl.Number, cl.Project.Project(), cl.Number, m.Meta.Hash.String())
 		b.postGitHubMessageNoDup(ctx, repo.GetOwner().GetLogin(), repo.GetName(), pr.GetNumber(), msg)
 	}