Adding a name to notable releases

The idea

When particular release contains a significant new feature, we'll add short name for that feature (set of features) in the release header.

Why

Release name should provide value in two ways:

• When we link the CHANGELOG during the release, it will be easier for users/stakeholders to spot what has happened
• It makes it easier to find important release of the past

How

The release header will have another optional section

- # <sem ver> - <date>
+ # <sem ver> - <date> [- <release name>]

The release name is using sentece case capitalization:

https://docs.gitlab.com/ee/development/documentation/styleguide.html#capitalization