Add details about Distribution team merge request handling

Why is this change being made?

Expanding on the roles of Distribution Engineers in the handling of merge requests. Encouraging the practice of not assigning MRs to lower the barrier for people to take part in the review process

Does this MR meet the acceptance criteria?

Assign to DRI

• Did you assign this change to the correct DRI of the page or information you are changing?

Conformity

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