Create a deployment FAQ

Create a page describing the symptoms of a deployment (like pending pipelines) which can be referred to from a deployment announcement.

It should also answer the following questions:

• How long does a deployment usually take?
• Why does the deployment happen during working hours?
• Why can't the deployment happen on the weekend?
• Why do we deploy RCs to gitlab.com?

After this page has been created, templates for release issues need to be updated: https://gitlab.com/gitlab-org/release-tools/tree/master/templates