added clarifcation on features.yml in post MR

Why is this change being made?

It was unclear from the existing release post instructions template whether or not changes to features.yml should be included in the same MR with the new feature yaml files. Added a clarification that it should be done in the same MR.

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