Making the main page of the handbook pretty, like the marketing handbook
Fixes https://gitlab.com/gitlab-com/peopleops/issues/62
\cc @virtuacreative @lukebabb @sytses @AshleyS
Do not update/delete: Banner broadcast message test data
Do not update/delete: Notification broadcast message test data
Fixes https://gitlab.com/gitlab-com/peopleops/issues/62
\cc @virtuacreative @lukebabb @sytses @AshleyS