Document Gitaly, GitLab Pages, GitLab Runner, GitLab QA in the developer onboarding page
As discussed in https://gitlab.com/gitlab-com/organization/issues/66#note_26931350, a few components are not listed in the developer onboarding page.
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
As discussed in https://gitlab.com/gitlab-com/organization/issues/66#note_26931350, a few components are not listed in the developer onboarding page.