Update comm writers guidelines
Closes https://gitlab.com/gitlab-com/community-writers/issues/154
Update pre-assessment stage of the community writers: follow up via confidential issues instead of email.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Closes https://gitlab.com/gitlab-com/community-writers/issues/154
Update pre-assessment stage of the community writers: follow up via confidential issues instead of email.