Add new Release groups

Why is this change being made?

Due to team splits happening in FY21 (and now) we're separating group pages to allow those pages to accurately represent those groups.

Adds directories for the new release stage groups
Adds files for release stage groups

Does this MR meet the acceptance criteria?

Conformity

• Added description to this MR explaining the reasons for the proposed change, per say-why-not-just-what