Reduce manual checkbox actions in Release Post item template

Why is this change being made?

The overall number of manual actions in the Release Post Item checklist has reached a total of 43 items. Given the number of release post items to review, this is a small quality of life change that moves the checkboxes onto the section level. This reduces the number from 43 to 16 (~63% reduction). A note was added to clarify that sections should only be checked if all individual items were evaluated. This should reduce the overall burden on team members, while ensuring quality of content.

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