Improve rollout issue with explicit language for enabling a feature flag globally

Corrective action from issue #345417 (closed)

Per gitlab-com/gl-infra/delivery#2112 (closed) , we should improve the language of the feature flag rollout to be more explicit about when to mention #support_gitlab-com and automate the posting when a feature flag has been enabled globally. I suggest that we perhaps strengthen the language to mention the feature flag no matter what since it's hard to know if something is user-visible.

Feature Flag Roll Out.md template

Edited by Alina Mihaila