Document additional steps to follow in PM process

Why is this change being made?

Adding additional steps that engineering had the right to punt things that probably can’t be completed in the upcoming sprint and should be broken down further but time has run out.

cc @sfwgitlab @kencjohnston

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